High

Performance
Flanged Safety Relief Valves
Series 441
Series XXL
Series 444

CATALOG 1
Product Range
LESER Safety Valves for every industrial application

High
Performance

Compact Series 441

Performance
Type 441, 442 DIN
Type 441, 442 ANSI

API

Series XXL

Type 441, 442 XXL

High
Efficiency

Series 444
Clean
Type 444 DIN
Service
Type 444 ANSI

Critical
H 2 SO 4
HNO 3 Service Series 441 Full nozzle
NH 3
HCL Type 441, 442 Full nozzle DIN

Type 441, 442 Full nozzle ANSI

Modulate
Action fer to
l e a se re ance
P rm
i g h Perfo 2
H log
Series 458 Cata

Best Type 455, 456

Availability Type 457, 458
General
Type 441, 442 DIN
DN 20, 40, 50
Set pressure 0.1 – 40 bar, 1.5 – 580 psig
Flanges according to DIN EN 1092

Type 441, 442 ANSI

Valve size 1" – 4"
Set pressure 0.1 – 51 bar, 1.5 – 740 psig
Flanges according to ASME B16.5

Type 441, 442 XXL

DN 200 – 400, 8" – 16"
Set pressure 0.2 – 25 bar, 3 – 360 psig
Flanges according to DIN EN 1092 and ASME B16.5

Type 444 DIN

DN 25 – 80
Set pressure 0.1 – 16 bar, 1.5 – 232 psig
Flanges according to DIN EN 1092

Type 444 ANSI

Valve size 1" – 3"
Set pressure 0.1 – 16 bar, 1.5 – 232 psig
Flanges according to ASME B16.5

Options
Contents
Overview Chapter/Page Type 441, 442 ANSI 02/01
Materials
General 00/01 • Conventional design 02/02
• Balanced bellows design 02/04
Applications, General design features 00/02
How to order
Valve finder 00/03 • Numbering system 02/06
• Article numbers 02/08
Valve selection 00/05
Dimensions and weights
How to use: • Metric Units 02/10
Signs and symbols, Flange drillings and facings 00/07 • US Units 02/11
Pressure temperature ratings
How to use:
• Metric Units 02/12
Determination of coefficient of discharge Kdr / α w 00/08
• US Units 02/13
How to use: Capacity sheets 00/09 Flange drillings and facings 02/14
Order information – Spare parts 02/15
LESER Effective Orifice LEOS/G 00/11 Available options 02/16
Approvals 02/17
LESER Effective Orifice LEOL 00/12
Capacities
Sour gas service 00/13 • Steam [Metric Units + US Units] 02/18
• Air [Metric Units + US Units] 02/19
• Water [Metric Units + US Units] 02/20
Determination of coefficient of discharge Kdr / α w 02/21

LESER Type Chapter/Page

Type 441, 442 DIN 01/01 Type 441, 442 XXL 03/01
Materials Materials
• Conventional design 01/02 • Conventional design 03/02
• Balanced bellows design 01/04 • Balanced bellows design 03/04
How to order How to order
• Numbering system 01/06 • Numbering system 03/06
• Article numbers 01/08 • Article numbers 03/08
Dimensions and weights Dimensions and weights
• Metric Units 01/10 • Metric Units 03/10
• US Units 01/11 • US Units 03/11
Pressure temperature ratings Pressure temperature ratings
• Metric Units 01/12 • Metric Units 03/12
• US Units 01/14 • US Units 03/13
Flange drillings and facings 01/16 Flange drillings and facings 03/14
Order information – Spare parts 01/18 Order information – Spare parts 03/15
Available options 01/20 Available options 03/16
Approvals 01/21 Approvals 03/17
Capacities Capacities
• Steam [Metric Units + US Units] 01/22 • Steam [Metric Units + US Units] 03/18
• Air [Metric Units + US Units] 01/24 • Air [Metric Units + US Units] 03/19
• Water [Metric Units + US Units] 01/26 • Water [Metric Units + US Units] 03/20
Determination of coefficient of discharge Kdr / α w 01/28 Determination of coefficient of discharge Kdr / α w 03/21

Type 441 Type 441 Type 441 Type 444

Cap H2 Packed lever H4 Plain lever H3 Packed lever H4
Closed bonnet Closed bonnet Closed bonnet Closed bonnet
Conventional design Conventional design Conventional design Conventional design

Type 441 Type 442 Type 444

Cap H2 Plain lever H3 Cap H2
Closed bonnet Open bonnet Closed bonnet
Balanced bellows design Conventional design Conventional design
 Contents

Type 444 DIN 04/01 Options

Materials Soft seal 99/12
• Conventional design 04/02 Balanced bellows 99/14
How to order High temperature equipment 99/16
• Numbering system 04/04 Elastomer bellows 99/17
• Article numbers 04/06 Disc 99/18
Dimensions and weights Heating jacket 99/20
• Metric Units + US Units 04/07 O-ring damper 99/22
Pressure temperature ratings Lift indicator 99/24
• Metric Units + US Units 04/08 Lift restriction 99/25
Flange drillings and facings 04/09
Order information – Spare parts 04/10
Available options 04/11
Approvals 04/12
Capacities
• Steam [Metric Units + US Units] 04/13
Type 441, 442 Full nozzle
• Air [Metric Units + US Units] 04/14 Materials
• Water [Metric Units + US Units] 04/15 How to order
Dimensions and weights
Determination of coefficient of discharge Kdr / α w 04/16 Pressure temperature ratings
talogzzle
Flange drillings and facings to ca o
refer 41 Full n
Order information – Spare parts 4
Type 444 ANSI 05/01 S eries
Available options
Materials Approvals
• Conventional design 05/02 Capacities
How to order Determination of coefficient of discharge Kdr / α w
• Numbering system 05/04
• Article numbers 05/06
Type 455, 456
Dimensions and weights
Materials
• Metric Units + US Units 05/07
How to order
Pressure temperature ratings Dimensions and weights
• Metric Units + US Units 05/08 Pressure temperature ratings
talog
Flange drillings and facings to ca
Flange drillings and facings 05/09 refereries 458
Order information – Spare parts S
Order information – Spare parts 05/10
Available options
Available options 05/11
Approvals
Approvals 05/12 Capacities
Capacities Determination of coefficient of discharge Kdr / α w
• Steam [Metric Units + US Units] 05/13
• Air [Metric Units + US Units] 05/14
• Water [Metric Units + US Units] 05/15 Type 457, 458
Determination of coefficient of discharge Kdr / α w 05/16 Materials
How to order
Dimensions and weights
Options 99/01 Pressure temperature ratings
talog
Flange drillings and facings to ca
Overview 99/02 refereries 458
Order information – Spare parts S
Caps and Levers 99/04 Available options
Caps and Levers bolted 99/06 Approvals
Metal seat 99/08 Capacities
Soft seal disc 99/10 Determination of coefficient of discharge Kdr / α w

talog talog talog talog

to ca nozzle to ca 8 to ca 8 to ca 8
refer F u ll refer s 4 5 refer s 4 5 refer s 4 5
s 44
1 Serie Serie Serie
Serie

Type 441 XXL Type 441 Full Nozzle Type 456 Type 457 Type 458
Bolted lifting device H6 Cap H2 Packed lever H4 Plain lever H3 Cap H2
Closed bonnet Closed bonnet Closed bonnet Open bonnet Closed bonnet
Conventional and balanced Conventional design Conventional design Conventional design Balanced bellows design
bellows design
 General Information
General

LESER – High Performance Safety Valves

The High Performance product group represents

✓ High capacity related to the safety valve size

✓ High adaptability
✓ Excellent price / performance ratio

LESER´s High Performance Safety Valves

• Are designed to meet all industrial applications.

• Open rapidly with an overpressure of 5 % to the full design lift.
• Are used particularly for vapours and gases where
the maximum mass flow has to be discharged rapidly.
• Have a maximum blowdown of minus 10 % for steam/
gas service and minus 20 % for liquid service.
• Are one of the best selling spring loaded safety valve
worldwide.
• Are developed in a close cooperation with plant engineers
and service specialists.
• Serve for protection of processes and equipment.

• Are approved by all important approval organisations world-

wide which ensures the worldwide applicability e.g.:

• European Community: CE-marking acc. to Pressure

Equipment Directive (PED) 97 / 23 / EC and EN ISO 4126-1
• USA: UV-stamp acc. to ASME Section VIII Division 1,
National Board certified capacities
• Germany: VdTÜV approval acc. to PED, EN ISO 4126-1,
TÜV SV 100 and AD 2000-Merkblatt A2
• Canada: Canadian Registration Number acc. to the
requirements of particular provinces
• China: AQSIQ based on the approval acc. to ASME
Section VIII Division 1 and AD 2000-Merkblatt A2

Furthermore, all LESER High Performance safety valves

are designed, marked, produced and approved acc. to the
requirements of the following regulations (directives, codes,
rules and standards).

EN ISO 4126-7, EN 12266-1/-2, EN 1092 Part I and II flanging

ASME PTC 25, ASME-Code Sec. II, ASME B 16.34 and ASME
B16.5-flanging, API Std. 527, API RP 576
AD 2000-Merkblatt A4, AD 2000-Merkblatt HP0, TRD 110,
TRD 421, TRD 721

00/01 LWN 482.01-E

General Information

General
Applications General Design Features

LESER – High Performance Safety Valves LESERs High Performance Safety Valves

Are the ultimate solution for all industrial Offer a large variety of types, materials and options
applications for steam, gas and liquid. to suit any application:

Typical applications for • 14 valve sizes from DN 20 to DN 400 – 3/4" to 16"

LESER High Performance Safety Valves are: provide a high connectivity to the application
• Inlet pressure ratings PN 16 to PN 400 / class 150 to
Series 441 class 2500 to fit all required design pressures
• Protection of chemical processes and equipment • Orifice sizes from E to > 3 x T cover all capacity
(e.g. distillation columns) requirements
• Heat exchangers • Large variety of body materials; e.g.
• Low and medium pressure steam

• Blowers and turbo compressors • 0.6025 / grey iron

• 0.7043 / ductile iron
• 1.0619 / WCB
Series XXL
• 1.4408 / CF8M
• Low pressure steam at big power stations
• 1.7357 / WC6
• Capacities beyond the limits of API and Series 441
can be selected acc. to the application
Series 444
• OEM in dying machines or filter constructions • Set pressures from 0.1 to 300 bar / 1.5 to 4350 psig
• Stainless steel applications up to 16 bar / 232 psig
make this product group suitable for all industrial processes
• Operating temperatures from -270 to 550 °C / -454 to
1022 °F cover a wide range of applications
Series 441 Full Nozzle
• One design and spring (single trim) for steam, gas and
• Same applications like Series 441 when
liquid applications reduces the number of spare parts and
full nozzle design is preferred.
ensure an easier maintenance
• Special requirement for nozzle material
• High capacity compared to the API requirements to reduce
installation costs
Series 458
• Ringless design needs no trim adjustments
• Power stations and industrial superheated
for easy maintenance
steam generation
• One-piece spindle reduces friction which is leading to
• Required flange classes ≥ PN 63 / CL600
high operation accuracy
• Protection of high pressure Chemical processes,
• Self-draining body design, avoids residues and reduces
e.g. NH3 synthesis, CO2 extraction
corrosion
• Desalination plants

LESERs High Performance Safety Valves

can be customized with a great variety of options, e.g.

• O-ring disc for superior tightness

• Stellited or hardened metal sealing for longer product life
• Stainless steel bellows for back pressure compensation
• Heating jacket for applications with high viscosity fluids
• Every part can be replaced by other material acc. to
customer specification

LWN 482.01-E 00/02

 Valve finder
General

How to find the right Product Group

controlled
High

Medium-
High operating to set
Yes
pressure ratio, high backpressure Efficiency
or low total height?

No

Clean
Clean Service Yes
application? Service

No

Critical
Critical Service / highly corrosive Yes
application? Service

No

Safety Valves
API
API specified Yes
application?

Spring loaded
No

Steam, gas and liquid application Modulate

Yes
with low capacity in relation Action
to the valve size?

No

Orifice ≥ F High
Performance

Required
Orifice letter?
Compact
Performance
Orifice ≤ F
over valve
Change-

Bursting

Best
disc

Additional components Yes

beyond safety valves Availability

00/03 LWN 482.01-E

Valve finder

General
How to find the right Safety Valve

DIN EN 1092 Type 441 DIN

Type 442 DIN

ASME B16.5 Type 441 ANSI

Flange standard? Type 442 ANSI

No
DIN EN 1092 Type 441 Full nozzle DIN
Type 442 Full nozzle DIN

Yes ASME B16.5 Type 441 Full nozzle ANSI

Full nozzle-design required?
Type 442 Full nozzle ANSI

≤ PN40 / CL300 ≥ PN63 / ≥ CL600

Serie 458

Semi nozzle up to
Flange rating? 100 bar / 1450 psig Type 455
Type 456
Full nozzle up to
400 bar / 5800 psig Type 457
Type 458
≤ DN 150 / 6"

≥ DN 200 / 8" Type 441 XXL

Valve size, inlet? Type 442 XXL

General industry

DIN EN 1092
up to Type 444 DIN
16 bar /
Stainless steel 232 psig ASME B16.5
Type 444 ANSI
OEM-application?

How to find
the right Hig Performance
Safety Valve

LWN 482.01-E 00/04

 Valve selection
General

Valve size
Type 441, 442 441, 442 441, 442 444 444 441, 442 441, 442 455, 456 457, 458
DIN ANSI XXL DIN ANSI Full nozzle Full nozzle
DIN ANSI

DN 20 (DN 25) DN 200 DN 25 – DN 25 (DN 25) DN 25 DN 25

min.
(3/4") 1" 8" – 1" (1") 1" 1" 1"
DN 200 (DN 100) DN 400 DN 80 – DN 50 (DN 100) DN 100 DN 150
max.
(8") 4" 16" – 3" (2") 4" 4" 6"

Materials
Type 441, 442 441, 442 441, 442 444 444 441, 442 441, 442 455, 456 457, 458
DIN ANSI XXL DIN ANSI Full nozzle Full nozzle
DIN ANSI

0.6025 Grey iron ✓ – – – – – – – –

0.7043 Ductile Gr. 60-40-18 ✓ – – – – – – – –
1.0619 WCB ✓ ✓ – – – ✓ ✓ ✓ ✓
1.0460 / 1.0425 Carbon steel – – ✓ – – – – – –
1.4408 CF8M ✓ ✓ – – – ✓ ✓ – –
1.4404 316L – – – ✓ ✓ – – – –
1.4581 CF10M – – – – – – – ✓ ✓
1.4571 316Ti – – ✓ – – – – – –
1.7357 WC6 – – – – – – – ✓ ✓

Set pressure
Type 441, 442 441, 442 441, 442 444 444 441, 442 441, 442 455, 456 457, 458
DIN ANSI XXL DIN ANSI Full nozzle Full nozzle
DIN ANSI

Metric Units min. [bar] 0.1 0.1 0.2 0.1 0.1 0.1 0.1 2.5 2.5
US Units min. [psig] 1.5 3 3 1.5 1.5 1.5 1.5 36 36
Metric Units max. [bar] 40 51 25 16 16 40 51 100 300
US Units max. [psig] 580 740 360 232 232 580 740 1450 4350

00/05 LWN 482.01-E

Valve selection

General
Temperature range
Type 441, 442 441, 442 441, 442 444 444 441, 442 441, 442 455, 456 457, 458
DIN ANSI XXL DIN ANSI Full nozzle Full nozzle
DIN ANSI

acc. to DIN EN min. [°C] -270 -270 -196 -45 -45 -270 -270 -85 -270
max. [°C] 450 450 550 200 200 450 450 550 550
min. [°F] -454 -454 -321 -49 -49 -454 -454 -121 -454
max. [°F] 842 842 1022 392 392 842 842 1022 1022
acc. to ASME min. [°C] -268 -268 -184 -45 -45 -268 -268 -129 -268
max. [°C] 538 538 427 200 200 538 538 538 538
min. [°F] -450 -450 -300 -49 -49 -450 -450 -20 -450
max. [°F] 1000 1000 800 392 392 1000 1000 1000 1000

Capacity
Type 441, 442 441, 442 441, 442 444 444 441, 442 441, 442 455, 456 457, 458
DIN ANSI XXL DIN ANSI Full nozzle Full nozzle
DIN ANSI

LEOS/G min. 0.283 0.462 23.8 0.462 0.462 0.462 0.462 0.399 0.224
LEOS/G max. 23.8 7.39 76.0 4.78 4.78 1.85 7.39 5.46 11.4
OrificeS/G min. 1.4 x E 1.5 x F 1.5 x R 1.5 x F 1.5 x F 1.5 x F 1.5 x F 1.3 x F 1.1 x E
OrificeS/G max. 1.5 x R 1.2 x P 3.0 x T 1.1 x N 1.1 x N 1.0 x K 1.2 x P 1.3 x N 1.0 x Q
LEOL min. 0.316 0.516 26.6 0.516 0.516 0.516 0.516 0.429 0.241
LEOL max. 26.6 8.26 84.9 5.34 5.34 2.07 8.26 5.87 10.9
OrificeL min. 1.0 x F 1.0 x G 1.0 x T 1.0 x G 1.0 x G 1.0 x G 1.0 x G 1.4 x F 1.2 x E
OrificeL max. 1.0 x T 1.3 x P 33 x T 1.2 x N 1.2 x N 1.1 x K 1.3 x P 1.4 x N 1.7 x P

Approvals
Type 441, 442 441, 442 441, 442 444 444 441, 442 441, 442 455, 456 457, 458
DIN ANSI XXL DIN ANSI Full nozzle Full nozzle
Country Code Media DIN ANSI

DIN EN ISO 4126-1 07 202 0111Z0008/0/11

Europe S/G/L 07 202 0111Z0008/0/08 Rev. 3
CE-marking Rev. 1
AD 2000- TÜV SV TÜV SV TÜV SV TÜV SV TÜV SV TÜV SV TÜV SV TÜV SV TÜV SV
Germany S/G/L
Merkblatt A2 576 576 576 576 576 576 576 934 934
M37066 M37066
S/G M37044 M37044 M37044 M37044 M37044 M37044 M37044
United M37088 M37088
ASME VIII
States M37077 M37077
L M37055 M37055 M37055 M37055 M37055 M37055 M37055
M37099 M37099
Canada CRN S/G/L ✓ ✓ ✓ ✓ ✓ ✓ ✓ – –
China AQSIQ S/G/L ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Russia GOST R / RTN ✓ ✓ ✓ ✓ ✓ – – ✓ ✓
Classification societies
Bureau Veritas BV ✓ ✓ ✓ – – – – – –
Det Norske Veritas DNV ✓ ✓ – – – – – – –
Germanischer Lloyd GL ✓ ✓ ✓ – – – – – –
Lloyd`s register EMEA LREMEA ✓ ✓ ✓ – – – – – –
Registro Italiano Navale RINA ✓ ✓ up to DN 250 – – – – – –

LWN 482.01-E 00/06

 How to use
General

General signs and symbols

This option is covered by standard design

*
✓ Available

– Not possible

Signs and symbols for flange drillings and flange facings

Standard design, no option code required

*
– Flange drilling/facing is not possible

Flange dimensions except flange thickness are in accordance with flange standard (e.g. ASME B16.5)
(*)
Flange thickness is smaller (max. 2 mm), see “Multiple pressure rating”.

Option code for flange drilling and dimension, e.g. H50

Flange drilling as specified in flange standard

H50
Outer flange diameter, flange thickness and height of flange facing may be larger, see “Dimensions”

Flange dimensions except flange thickness are in accordance with standard

(H50)
Flange thickness is smaller (max. 2 mm), see “Multiple pressure rating”

Flange drilling as specified in standard/flange thickness may be smaller

[H50] Outer flange diameter is smaller than required, but complete back side facing for nut is assured

Option code for flange facing, e.g. L36

L36 Flange facing as specified in flange standard (e.g. Flange facing inlet Type B2 “smooth finish”)

General information concerning flange drillings and flange facings

Multiple The flange standard shows the same drilling, facing and outer diameter for several pressure ratings, e.g. PN 16 up to PN 40
pressure rating Due to the pressure rating of the casting LESER fulfils the requirements for flange thickness e.g. of PN 16 but not PN 40

The effective MSS SP-6 (Edition 2001) does not mention “smooth finish” anymore.
In MSS SP-6 (Edition 1980) “smooth finish” is defined for finishes of contact flanges as “250 μinch (6.3 μm) AARH max.”.
Smooth finish
LESER supplies flange facings according to ASME B16.5 – 1996, paragraph 6.4.4.3:
“Either a serrated concentric or serrated spiral finish resulting in service finish from 125 μinch to 250 μinch average
roughness shall be furnished.” This finish meets the requirements of MSS SP-6 (Edition 1980), which is not valid anymore!
Stock finish is not defined in any technical standard. If purchase orders show “stock finish” LESER supplies standard
Stock finish
facing according to DIN or ASME (marked with * in table “Flange facings” of each valve series).

Materials
Please find below a summary of material codes at LESER. Please note that
- for every body material an inspection certificate 3.1 according to EN 10204 is available
- many materials have a multiple inspection certificate 3.1.
Body material is certified with 3.1 (EN 10204) for the following materials
Material code Flanged safety valve body
DIN EN ASME
xxx 1.xxxx Grey iron 0.6025 cast iron
xxx 2.xxxx Carbon steel 1.0619 WCB, WCC
xxx 4.xxxx Stainless steel 1.4408, 1.4581 CF8M (Charpy test at -196°C), CF10M
xxx 5.xxxx Nodular cast iron 0.7043 ductile Gr. 60-40-18
xxx 7.xxxx High temperature carbon steel 1.7357 WC6

00/07 LWN 482.01-E

How to use

General
Sample Determination of Kdr /αw : Type 441, DIN, DN 25

Type 441, 442 DIN

Determination of coefficient of discharge h = Lift [mm]
d0 = Flow diameter [mm] of selected safety
in case of lift restriction or back pressure valve, refer to table article numbers
h/d0 = Ratio of lift / flow diameter
pa0 = Back pressure [bara]
p0 = Set pressure [bara]
pa0 / p0 = Ratio of back pressure / set pressure
Diagram for evaluation of ratio of lift / flow diameter (h/d0) Kdr = Coefficient of discharge
acc. to DIN EN ISO 4126-1
in reference to the coefficient of discharge (Kdr /αw) αw = Coefficient of discharge
acc. to AD 2000-Merkblatt A2
1 Kb = Back pressure correction factor
acc. to API 520 topic 3.3
Kdr = αw = f (h/d0)
0.800

DN 20 – 100 S/G
0.700

DN 200 cast S/G

0.600

1a DN 125 – 150, S/G

0.500
DN 200 cast L
0.45
0.400
Coefficient of discharge Kdr / αw

DN 20 – 100 L
0.300

DN 125 – 150, L
0.200

0.100

0
0 0.050 0.100 0.150 0.200 0.250 0.300
0.21 0.243 0.270
Ratio of lift / flow diameter h / d0

1b 0.13

Diagram for evaluation of coefficient of discharge (Kdr /αw) or Kb

in reference to the ratio of back pressure / set pressure (pa0 / p0)
2
Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0)
0.8

0.7 1.0
2b 2b
0.9
0.6
0.595 0.8
0.85
0.5 0.7

0.6
Back pressure correction factor Kb

0.4
Coefficient of discharge Kdr / αw

0.5
0.3
0.4

0.2 0.3

0.2
0.1
0.1

0 0
0.2 0.3 0.4 0.5 0.6 0.7 0.8
0.91
Ratio of back pressure / set pressure pa0 / p0

2a 0.648

Explanation Sample – Type 441 DIN, DN 25, flow diameter d0 = 23 mm, rated lift h = 5.6 mm, Kdr /αw S/G = 0.7
Diagram 1 Diagram 2
1 2
Determination of the restricted lift due to reduced Kdr /αw Determination of reduced Kdr /αw or Kb1) due to back pressure
Step Description Sample Step Description Sample
Calculate the required coefficent of discharge of 1a Calculate the back pressure ratio pa0 / p0 using the
1 the selected safety valve. Applicable formulars 1 actual values for set pressure p0 [bara] 0.45
are stated in codes and standards. Kdr /αw = 0.45 and back pressure pa0 [bara] 0.292 pa0 /p02a
= 0.648

Select the starting point (0.45) at the Y-axis of Select the starting point (0.648) at the X-axis
2 2
the diagram. of the diagram.

Lay a horizontal line onto the ratio graph to Lay a vertical line onto the ratio graph to
3 3
identify the intersection point. identify the intersection point.

Lay a vertical line to the X-axis to identify the 1b Lay a horizontal line to the Y-axis to Kdr /αw = 0.595
4 4 2b
ratio of lift / flow diameter (h/d0). h/d0 = 0.13 identify the reduced Kdr /αw or Kb. Kb = 0.85
Calculate the restricted lift using the formular
h = 23 x 0.13 Calculate the sizing with the established
5 h = d0 x h/d0. (For ordering a lift restriction 5
h = 3 mm Kdr /αw or Kb.
please use option code J51 refer to page 99/25)
1) Back pressure correction factor Kb acc. to API 520 topic 3.3. For further information refer to ENGINEERING at www.leser.com/engineering.

LWN 482.01-E 00/08

 How to use
General

Sample Capacity sheet –

How to select capacities for steam: Type 441 XXL DIN, DN 250

Capacities – Steam

Capacities for saturated steam according to AD 2000-Merkblatt A2, Capacities for saturated steam according to ASME Section VIII (UV),
based on set pressure plus 10 % overpressure. based on set pressure plus 10% overpressure.
9

Capacities at 1 bar (14.5 psig) and below are based on 0.1 bar Capacities at 2.07 bar (30 psig) and below are based on 0.207 bar
(1.45 psig) overpressure. (3 psig) overpressure.

1
Metric Units AD 2000-Merkblatt A2 [kg/h] US Units ASME Section VIII [lb/h]

DN I+O 200 x 300 250 x 350 2 300 x 400 400 x 500 DN I+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 3 10" x 14" 12" x 16" 16" x 20" Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Act. Orifice dia. d0 [mm] 165 200 4 235 295 Act. Orifice dia. d0 [inch] 6.5 7.87 9.25 11.61
Act. Orifice area. d0 [mm] 21382 5 31416 43374 68349 Act. Orifice area. d0 [inch2] 33.14 48.69 67,23 105.94
LEOS/G*) [inch2] 23.761 34.910 6 48.198 75.952 LEOS/G*) [inch2] 23.761 34.910 48.198 75.952
Set pressure [bar] 7 Capacities [kg/h] Set pressure [psig] Capacities [lb/h]
0.1 0 0 0 0 15 38962 57245 79034 124543
0.2 7214 0 14633 0 20 44928 66009 91134 143612
0.5 11516 16920 23360 36811 30 56859 83539 115336 181749
1 16755 24617 8 33986 53556 40 69983 102821 141958 223700

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

Explanation Type 441 XXL

No. Description Metric Units US Units Example

1 Code AD 2000-Merkblatt A2

2 Nominal diameter inlet x outlet DNI+O 250 x 350

3 Valve size 10" x 14"

4 Actual orifice diameter d0 [mm] [inch] 200

5 Actual orifice area A0 [mm2] [inch2] 31416

6 LESER Effective Orifice LEOS/G [inch2] [inch2] 34.910

7 Set pressure [barg] [psig] 1

8 Capacity [kg/h] [lb/h] 24617

9 Base of calculation see table page 00/10

00/09 LWN 482.01-E

 How to use

General
9

Base of calculation
Metric Units US Units
Capacity calculation according to Capacity calculation according to
Code
AD 2000-Merkblatt A2 ASME Section VIII (UV)

Steam table IAPWS-IF97 Steam table IAPWS-IF97

STEAM Standard IAPWS Industrial Formulation for IAPWS Industrial Formulation for
[kg/h] [lb/h]
(saturated steam) conditions the Thermodynamic Properties the Thermodynamic Properties
of Water and Steam of Water and Steam

Standard
AIR 0 °C and 1013 mbar [mn3/h] 16 °C (60 °F) [S.C.F.M.]
conditions

Standard
WATER 20 °C (68 °F) [103 kg/h] 21 °C (70 °F) [US-G.P.M.]
conditions

Calculation
Set pressure plus 10 % overpressure Set pressure plus 10 % overpressure
pressure

Calculation
Capacities at 1 bar (14.5 psig) Capacities at 2.07 bar (30 psig)
pressure
and below are based on 0.1 bar and below are based on
for low
(1.45 psig) overpressure. 0.207 bar (3 psig) overpressure.
set pressure

Example Capacity calculation pressure

Metric Units US Units

Set pressure Capacity calculation pressure Set pressure Capacity calculation pressure

10 bar 10 bar + 10% overpressure = 11 bar 145 psig 145 psig + 10% overpressure = 159.5 psig

0.5 bar 0.5 bar + 0.1 bar overpressure = 0.6 bar 20 psig 20 psig + 3 psig overpressure = 23 psig

LESER Effective Orifice

Pressure relief devices may be initially sized using the equa- specific valve design. In this way the designer can deter-
tions shown in API RP 520, sections 3.6 through 3.10 as mine a preliminary pressure relief valve size. By using the
appropriate for vapors, gases, liquids, or two phase flow. LESER Effective Orifice the designer can directly select a
These equations utilize effective coefficient of discharge (S/G LESER safety relief valve after calculating the orifice letter. In
0.975, L 0.650) and effective areas (acc. to API Std. 526, Fifth this case, a verification of the sizing with the selected actual
Edition, June 2002, table 1) which are independent of any orifice and the rated coefficient of discharge is not necessary.

LEOS/G LESER Effective Orifice (for steam, gas and vapor) [inch2] refer to page 00/11

LEOL LESER Effective Orifice (for liquid) [inch2] refer to page 00/12

For further information refer to LESER Engineering Handbook.

LWN 482.01-E 00/10

 LEOS/G
General

This table is based on the rated coefficient of discharge for steams and gases of LESER safety valves certified by ASME.
The appropriated K-values are shown in the column “K-value” of the table.

LEOS/G [inch2] = A0 [inch2] . ( 0.975

K
)
LEOS/G LESER Effective Orifice (for steam, gas and vapor)
LEOS/G % of next % of next
Orifice acc.
LESER-Series DN Inlet size d0 [inch] d0 [mm] K-value higher lower
API 526 [inch2] orifice orifice

D 0.110 100.0% 100.0%

E 0.196 100.0% 100.0%
458 25 1" 0.591 15.0 0.798 0.224 73.0% 114.4%
441 20 3/4" 0.709 18.0 0.699 0.283 92.1% 114.3%
F 0.307 100.0% 100.0%
458 25 1" 0.787 20.0 0.798 0.399 79.2% 129.8%
441 25 1" 0.906 23.0 0.699 0.462 91.8% 150.4%
441 Full nozzle 25 1" 0.906 23.0 0.699 0.462 91.8% 150.4%
444 25 1" 0.906 23.0 0.699 0.462 91.8% 150.4%
G 0.503 100.0% 100.0%
441 32 1 1/2" 1.142 29.0 0.699 0.734 93.5% 145.9%
441 Full nozzle 32 1 1/2" 1.142 29.0 0.699 0.734 93.5% 145.9%
H 0.785 100.0% 100.0%
458 50 2" 1.181 30.0 0.798 0.897 69.7% 114.2%
441 40 1 1/2" 1.457 37.0 0.699 1.195 92.8% 152.2%
441 Full nozzle 40 1 1/2" 1.457 37.0 0.699 1.195 92.8% 152.2%
444 40 1 1/2" 1.457 37.0 0.699 1.195 92.8% 152.2%
J 1.287 100.0% 100.0%
457. 458 50 2" 1.575 40.0 0.798 1.594 86.7% 123.9%
K 1.838 100.0% 100.0%
441 50 2" 1.811 46.0 0.699 1.847 64.7% 100.5%
441 Full nozzle 50 2" 1.811 46.0 0.699 1.847 64.7% 100.5%
444 50 2" 1.811 46.0 0.699 1.847 64.7% 100.5%
458 80 3" 1.969 50.0 0.798 2.491 87.3% 135.5%
458 100 4" 1.969 50.0 0.798 2.491 87.3% 135.5%
L 2.853 100.0% 100.0%
441 65 3" 2.362 60.0 0.699 3.142 87.3% 110.1%
441 Full nozzle 65 3" 2.362 60.0 0.699 3.142 87.3% 110.1%
444 65 2 1/2" 2.362 60.0 0.699 3.142 87.3% 110.1%
458 80 3" 2.362 60.0 0.754 3.389 94.1% 118.1%
458 100 4" 2.362 60.0 0.798 3.587 99.6% 125.7%
M 3.600 100.0% 100.0%
N 4.340 100.0% 100.0%
441 80 – 2.913 74.0 0.699 4.779 74.9% 110.1%
444 80 3" 2.913 74.0 0.699 4.779 74.9% 110.1%
458 100 4" 2.913 74.0 0.798 5.456 85.5% 125.7%
P 6.380 100.0% 100.0%
458 100 4" 3.465 88.0 0.754 7.290 66.0% 114.3%
441 100 4" 3.622 92.0 0.699 7.387 66.9% 115.8%
441 Full nozzle 100 4" 3.622 92.0 0.699 7.387 66.9% 115.8%
441 125 5" 3.858 98.0 0.699 8.382 75.9% 131.4%
Q 11.050 100.0% 100.0%
458 150 6" 4.331 110.0 0.754 11.391 71.2% 103.1%
441 150 6" 4.921 125.0 0.699 13.637 85.2% 123.4%
R 16.000 100.0% 100.0%
441 200 8" 6.496 165.0 0.699 23.761 91.4% 148.5%
XXL 200 8" 6.496 165.0 0.699 23.761 91.4% 148.5%
T 26.000 100.0% 100.0%
XXL 250 10" 7.874 200.0 0.699 34.910 134.3%
XXL 300 12" 9.252 235.0 0.699 48.198 185.4%
XXL 400 16" 11.614 295.0 0.699 75.952 292.1%

00/11 LWN 482.01-E

LEOL

General
This table is based on the rated coefficient of discharge for liquids of LESER safety valves certified by ASME.
The appropriated K-values are shown in the column “K-value” of the table.

LEOL [inch2] = A0 [inch2] . ( 0.650

K
)
LEOL LESER Effective Orifice (for liquid)
LEOL % of next % of next
Orifice acc.
LESER-Series DN Inlet size d0 [inch] d0 [mm] K-value higher lower
API 526 [inch2] orifice orifice

D 0.110 100.0% 100.0%

E 0.196 100.0% 100.0%
458 25 1" 0.591 15 0.572 0.241 78.5% 123.0%
F 0.307 100.0% 100.0%
441 20 3/4" 0.709 18 0.521 0.316 62.9% 103.0%
458 25 1" 0.787 20 0.572 0.429 85.2% 139.6%
G 0.503 100.0% 100.0%
441 25 1" 0.906 23 0.521 0.516 65.8% 102.6%
441 Full nozzle 25 1" 0.906 23 0.521 0.516 65.8% 102.6%
444 25 1" 0.906 23 0.521 0.516 65.8% 102.6%
H 0.785 100.0% 100.0%
441 32 1 1/2" 1.142 29 0.521 0.821 6.38% 104.5%
441 Full nozzle 32 1 1/2" 1.142 29 0.521 0.821 6.38% 104.5%
458 50 1" 1.181 30 0.572 0.964 74.9% 122.8%
J 1.287 100.0% 100.0%
441 40 1 1/2" 1.457 37 0.521 1.336 72.7% 103.8%
441 Full nozzle 40 1 1/2" 1.457 37 0.521 1.336 72.7% 103.8%
444 40 1 1/2" 1.457 37 0.521 1.336 72.7% 103.8%
458 50 2" 1.575 40 0.572 1.714 93.3% 133.2%
K 1.838 100.0% 100.0%
441 50 2" 1.811 46 0.521 2.065 72.4% 112.3%
441 Full nozzle 50 2" 1.811 46 0.521 2.065 72.4% 112.3%
444 50 2" 1.811 46 0.521 2.065 72.4% 112.3%
458 80 3" 1.969 50 0.527 2.678 93.9% 145.7%
458 100 4" 1.969 50 0.527 2.678 93.9% 145.7%
L 2.853 100.0% 100.0%
458 80 3" 2.362 60 0.479 3.230 89.7% 113.2%
441 65 3" 2.362 60 0.521 3.513 97.6% 123.1%
441 Full nozzle 65 3" 2.362 60 0.521 3.513 97.6% 123.1%
444 65 1 1/2" 2.362 60 0.521 3.513 97.6% 123.1%
M 3.600 100.0% 100.0%
458 100 4" 2.362 60 0.572 3.857 88.9% 107.1%
N 4.340 100.0% 100.0%
441 80 – 2.913 74 0.521 5.343 83.3% 123.1%
444 80 3" 2.913 74 0.521 5.343 83.3% 123.1%
458 100 4" 2.913 74 0.572 5.866 91.9% 135.2%
P 6.380 100.0% 100.0%
458 100 4" 3.465 88 0.479 6.947 62.9% 108.9%
441 100 4" 3.622 92 0.521 8.259 74.7% 129.4%
441 Full nozzle 100 4" 3.622 92 0.521 8.259 74.7% 129.4%
441 125 5" 3.858 98 0.521 9.371 84.8% 146.9%
458 150 6" 4.331 110 0.479 10.855 98.2% 170.1%
Q 11.050 100.0% 100.0%
441 150 6" 4.921 125 0.521 15.246 95.3% 138.0%
R 16.000 100.0% 100.0%
T 26.000 100.0% 100.0%
441 200 8" 6.496 165 0.521 26.565 102.0%
XXL 200 8" 6.496 165 0.521 39.031 102.0%
XXL 250 10" 7.874 200 0.521 39.031 150.1%
XXL 300 12" 9.252 235 0.521 53.887 207.3%
XXL 400 16" 11.614 295 0.521 84.916 326.6%

LWN 482.01-E 00/12

 Sour gas service (H2S)
General

Normative basis

NACE MR0175-2003 Section 1.4.2.2 Low-pressure oil and gas multiphase systems: …
In accordance with NACE standard MR 0175-2003 sour gas service
means the presence of H2S in the following conditions:
Other Sour gas standards:
NACE MR0103-2003: Materials resistance to sulfide stress
Section 1.4.1.1 All gas, gas condensate, and sour crude oil cracking in corrosive petroleum
– When the partial pressure of H2S in a wet refining environments.
(water as a liquid) gas phase of a gas, gas
DIN EN ISO 15156-1: Petroleum and natural gas industries
condensate, or crude oil system is equal to or
– Materials for use in H2S containing
exceeds 0.003 bara (0.05 psia)
environments in oil and gas pro-
Exceptions are:
duction – Part 1: General principles
Section 1.4.2.1 Low-pressure gas for selection of cracking-resistant
When the total pressure is lower than materials (ISO 15156-1:2001)
4.5 bara (65 psia) Works standard: Please refer to LWN 001.91

General requirements for sour gas service

The above mentioned standards require a maximum hardness of 22 HRC for the most steels.
For the actual requirements of a specific material please refer to the applied standard.

LESER sour gas level

General: Sour gas material requirements must be fulfilled if pressure and partial pressure conditions according to the applied standard exist.

Based on these general statement LESER defines two sour gas level for safety valves:

Level 1 Level 2
Contact with the medium in Contact with the medium in
Part definition
closed position opened position
Conventional Balanced bellows Conventional Balanced bellows

Contact area

Pressure requirements Set pressure ≥ 4,5 bara (65 psia) Back pressure ≥ 4,5 bara (65 psia)
Safety valve operation closed closed / opened
Conventional Body / Nozzle
all
design Disc
Parts concerned Body / Nozzle
Balanced Body / Nozzle
Disc,
bellows design Disc
Bonnet spacer, Bellows
Necessary material modification
Body
Type Design Part Material Option code Material Option code
material
4412 DIN
Conventional Disc 1.4404 / 316L L44 Please choose balanced bellows design
4412 ANSI 1.0619
4412 Full nozzle DIN (WCB) Disc 1.4404 / 316L L44 1.4404 / 316L L44
Balanced bellows
4412 Full nozzle ANSI Balanced bellows 1.4571 / 316Ti J78 1.4571 / 316Ti J78
4414 DIN
Conventional No modification required No modification required
4414 ANSI 1.4408
4414 Full nozzle DIN (CF8M)
Balanced bellows Balanced bellows 1.4571 / 316Ti J78 1.4571 / 316Ti J78
4414 Full nozzle ANSI

1.0460/ Conventional Disc No modification required Please choose balanced bellows design
4412 XXL 1.0425
(Steel) Disc No modification required No modification required
Balanced bellows
Balanced bellows 1.4571 / 316Ti J78 1.4571 / 316Ti J78
1.4571 Conventional No modification required No modification required
4414 XXL
(316Ti) Balanced bellows Balanced bellows 1.4571 / 316Ti J78 1.4571 / 316Ti J78
4444 DIN 1.4404
Conventional No modification required No modification required
4444 ANSI (316L)
1.0619 Conventional Disc 1.4404 / 316L L44 Please choose balanced bellows design
4562, 4582 (WCB)
4587 1.7357 Disc 1.4404 / 316L L44 1.4404 / 316L L44
(WC6) Balanced bellows
Balanced bellows 1.4571 / 316Ti J78 1.4571 / 316Ti J78
1.4581 Conventional
4584 Not listed in NACE Not listed in NACE
(CF10M) Balanced bellows

00/13 LWN 482.01-E

 Type

Type 441, 442 DIN

Type 442 DIN
Plain lever H3
Open bonnet
Conventional design
441 DIN
442 DIN
Flanged Safety Relief Valves
– spring loaded

Contents Chapter/Page

Materials
• Conventional design 01/02
• Balanced bellows design 01/04
How to order
• Numbering system 01/06
• Article numbers 01/08
Dimensions and weights
• Metric Units 01/10
Type 441 DIN • US Units 01/11
Packed lever H4
Closed bonnet Pressure temperature ratings
Conventional design • Metric Units 01/12
• US Units 01/14
Flange drillings and facings 01/16
Order information – Spare parts 01/18
Available options 01/20
Approvals 01/21
Capacities
• Steam [Metric Units + US Units] 01/22
• Air [Metric Units + US Units] 01/24
• Water [Metric Units + US Units] 01/26
Determination of coefficient 01/28
of discharge Kdr /α w

LWN 482.01-E 01/01

 Type 441, 442 DIN
Conventional design
Type 441, 442 DIN

40 Cap H2

18 Adjusting screw

19 Lock nut

16 Upper spring plate

9 Bonnet

12 Spindle

54 Spring

17 Lower spring plate

55 Stud

56 Nut

14 Split ring

60 Gasket

8 Guide with bushing

57 Pin

61 Ball

7 Disc

5 Seat

1 Body

01/02 LWN 482.01-E

Type 441, 442 DIN
Conventional design

Type 441, 442 DIN

Materials
Item Component Type 4411 / 4421 DIN Type 4415 / 4425 DIN Type 4412 / 4422 DIN Type 4414 DIN

0.6025 0.7043 1.0619 1.4408

1 Body
Cast iron Ductile Gr. 60-40-18 SA 216 WCB SA 351 CF8M
1.4404 1.4404 1.4404 1.4404
5 Seat
316L 316L 316L 316L
1.4122 1.4122 1.4122 1.4404
7 Disc
Hardened stainless steel Hardened stainless steel Hardened stainless steel 316L
1.4104, 1.0501, 0.7040 1.4104, 1.0501, 0.7040 1.4104, 1.0501, 0.7040 1.4404
Guide
Chrome or carbon steel Chrome or carbon steel Chrome or carbon steel 316L
8
1.4104 tenifer 1.4104 tenifer 1.4104 tenifer –
with bushing
Chrome steel tenifer Chrome steel tenifer Chrome steel tenifer –
0.7040, 0.7043, 1.0619 0.7040, 0.7043, 1.0619 0.7040, 0.7043, 1.0619 1.4408, 1.4404, 1.4571
9 Bonnet Ductile Gr. 60-40-18, Ductile Gr. 60-40-18, Ductile Gr. 60-40-18, SA 351 CF8M,
SA 216 WCB SA 216 WCB SA 216 WCB SA 479 316L, SA 479 316Ti
1.4021 1.4021 1.4021 1.4404
12 Spindle
420 420 420 316L
1.4104 1.4104 1.4104 1.4404
14 Split ring
Chrome steel Chrome steel Chrome steel 316L
1.0718 1.0718 1.0718 1.4404
16/17 Spring plate
Steel Steel Steel 316L
Adjusting screw 1.4104 PTFE 1.4104 PTFE 1.4104 PTFE 1.4404 PTFE
18
with bushing Chrome steel PTFE Chrome steel PTFE Chrome steel PTFE 316L PTFE
1.0718 1.0718 1.0718 1.4404
19 Lock nut
Steel Steel Steel 316L
1.0718 or 0.7043 1.0718 or 0.7043 1.0718 or 0.7043 1.4404
40 Cap H2
12L13 or Gr. 60-40-18 12L13 or Gr. 60-40-18 12L13 or Gr. 60-40-18 316L
1.1200, 1.8159, 1.7102 1.1200, 1.8159, 1.7102 1.1200, 1.8159, 1.7102 1.4310
Spring standard
Carbon steel Carbon steel Carbon steel Stainless steel
54
1.4310 1.4310 1.4310 –
Spring optional
Stainless steel Stainless steel Stainless steel –
1.1181 1.1181 1.1181 1.4401
55 Stud
Steel Steel Steel B8M
1.0501 1.0501 1.0501 1.4401
56 Nut
2H 2H 2H 8M
1.4310 1.4310 1.4310 1.4310
57 Pin
Stainless steel Stainless steel Stainless steel Stainless steel
Graphite / 1.4401 Graphite / 1.4401 Graphite / 1.4401 Graphite / 1.4401
60 Gasket
Graphite / 316 Graphite / 316 Graphite / 316 Graphite / 316
1.3541 1.3541 1.3541 1.4401
61 Ball
Hardened stainless steel Hardened stainless steel Hardened stainless steel 316

Please notice:

- Modifications reserved by LESER

- If several materials are specified LESER defines the material.
- LESER can upgrade materials without notice.
- Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 01/03

 Type 441, 442 DIN
Balanced bellows design
Type 441, 442 DIN

40 Cap H2

18 Adjusting screw

19 Lock nut

16 Upper spring plate

9 Bonnet

12 Spindle

54 Spring

14 Split ring

17 Lower spring plate

55 Stud

56 Nut

8 Guide with bushing

11 Bonnet spacer

60 Gasket

22 Lift stopper

15 Bellows

57 Pin

61 Ball

7 Disc

5 Seat

1 Body

01/04 LWN 482.01-E

Type 441, 442 DIN
Balanced bellows design

Type 441, 442 DIN

Materials
Item Component Type 4411 / 4421 DIN Type 4415 / 4425 DIN Type 4412 / 4422 DIN Type 4414 DIN

0.6025 0.7043 1.0619 1.4408

1 Body
Cast iron Ductile Gr. 60-40-18 SA 216 WCB SA 351 CF8M
1.4404 1.4404 1.4404 1.4404
5 Seat
316L 316L 316L 316L
1.4122 1.4122 1.4122 1.4404
7 Disc
Hardened stainless steel Hardened stainless steel Hardened stainless steel 316L
1.4104, 1.0501, 0.7040 1.4104, 1.0501, 0.7040 1.4104, 1.0501, 0.7040 1.4404
Guide
Chrome or carbon steel Chrome or carbon steel Chrome or carbon steel 316L
8
1.4104 tenifer 1.4104 tenifer 1.4104 tenifer –
with bushing
Chrome steel tenifer Chrome steel tenifer Chrome steel tenifer –
0.7040, 0.7043, 1.0619 0.7040, 0.7043, 1.0619 0.7040, 0.7043, 1.0619 1.4408, 1.4404, 1.4571
9 Bonnet Ductile Gr. 60-40-18, Ductile Gr. 60-40-18, Ductile Gr. 60-40-18, SA 351 CF8M,
SA 216 WCB SA 216 WCB SA 216 WCB SA 479 316L, SA 479 316Ti
1.0460 1.0460 1.0460 1.4404
11 Bonnet spacer
Carbon steel Carbon steel Carbon steel 316L
1.4404 1.4404 1.4404 1.4404
12 Spindle
316L 316L 316L 316L
1.4104 1.4104 1.4104 1.4404
14 Split ring
Chrome steel Chrome steel Chrome steel 316L
1.4571 1.4571 1.4571 1.4571
15 Bellows
316Ti 316Ti 316Ti 316Ti
1.0718 1.0718 1.0718 1.4404
16/17 Spring plate
Steel Steel Steel 316L
Adjusting screw 1.4104 PTFE 1.4104 PTFE 1.4104 PTFE 1.4404 PTFE
18
with bushing Chrome steel PTFE Chrome steel PTFE Chrome steel PTFE 316L PTFE
1.0718 1.0718 1.0718 1.4404
19 Lock nut
Steel Steel Steel 316L
1.4404 1.4404 1.4104 1.4404
22 Lift stopper
316L 316L Chrome steel 316L
1.0718 or 0.7043 1.0718 or 0.7043 1.0718 or 0.7043 1.4404
40 Cap H2
12L13 or Gr. 60-40-18 12L13 or Gr. 60-40-18 12L13 or Gr. 60-40-18 316L
1.1200, 1.8159, 1.7102 1.1200, 1.8159, 1.7102 1.1200, 1.8159, 1.7102 1.4310
Spring standard
Carbon steel Carbon steel Carbon steel Stainless steel
54
1.4310 1.4310 1.4310 –
Spring optional
Stainless steel Stainless steel Stainless steel –
1.4401 1.4401 1.4401 1.4401
55 Stud
B8M B8M B8M B8M
1.4401 1.4401 1.4401 1.4401
56 Nut
8M 8M 8M 8M
1.4310 1.4310 1.4310 1.4310
57 Pin
Stainless steel Stainless steel Stainless steel Stainless steel
Graphite / 1.4401 Graphite / 1.4401 Graphite / 1.4401 Graphite / 1.4401
60 Gasket
Graphite / 316 Graphite / 316 Graphite / 316 Graphite / 316
1.3541 1.3541 1.3541 1.4401
61 Ball
Hardened stainless steel Hardened stainless steel Hardened stainless steel 316

Please notice:

- Modifications reserved by LESER

- If several materials are specified LESER defines the material.
- LESER can upgrade materials without notice.
- Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 01/05

 Type 441, 442 DIN
How to order – Example for numbering system
Type 441, 442 DIN

1 Article Number
2 Set Pressure
3 Connections

4412.4512 5 barg H45

Please state unit (in gauge)! Please refer to page 01/16 and 01/17
1 2 3 4
Please do not exceed the pressure
441 2 . 451 2 range defined in the spring charts.

1 Valve Type 441, 442 DIN

Type 441 – with closed bonnet
Type 442 – with open bonnet

2 Material code

Code Lifting lever

1 0.6025 (cast iron)
2 1.0619 (WCB)
4 1.4408 (CF8M)
0.7043
5
(ductile Gr. 60-40-18)

3 Valve code
Identifies valve size and body
material, refer to page 01/09.

Code Lifting lever

2 screwed cap H2
3 plain lever H3
4 packed lever H4
plain lever
5 with open H3
bonnet

01/06 LWN 482.01-E

Type 441, 442 DIN

Type 441, 442 DIN

4 Options
5 Documentation
6
Code and Medium

J22 H01 L30 2.0

Type 441, 442 DIN Option code Please select required documentation:
1 2
Inspections, tests: Option code
• O-ring-disc
DIN EN 10204-3.2: TÜV-Nord
2 . 0
CR “K” J21 Certificate for test pressure M33
EPDM “D” J22 1 Code
FKM “L” J23 1. ASME Section VIII
LESER CGA (Certificate H03
FFKM “C” J20
for Global Application) 2. CE / VdTUEV
• Disc 1.4404 / 316L L44 - Inspection certificate 3.1 acc. 3. ASME Section VIII
to DIN EN 10204 + CE / VdTUEV
• Disc 1.4404 / 316L stellited J25
• Detachable lifting aid J26 - Declaration of conformity acc.
• Stainless steel bellows to PED 97/23/EC
2 Medium
- open bonnet (Type 442) J68
Material test certificate: .1 Gases
- closed bonnet (Type 441) J78
DIN EN 10204-3.1 .2 Liquids
• Elastomer bellows J79
.3 Steam
• High temperature alloy spring X01
Part Option code .0 Steam / Gases / Liquids
• Stainless steel spring X04 (valid only for CE / VdTUEV)
Body H01
• Adaptor for lift indicator H4 J39
Bonnet L30
• Lift indicator J93
Cap / lever cover L31
• Test gag
Nozzle L59
- cap H2 J70
Disc L23
- packed lever H4 J69
Studs N07
• Heating jacket
Nuts N08
- Couplings G 3/8 H29
G 3/4 H30
- Flanges DN 15 H31
DN 25 H32
• Drain hole G 1/4 J18
G 1/2 J19
• Free of oil and grease J85
• Materials
- NACE N78

Option code applies

only if not standard

LWN 482.01-E 01/07

 Type 441, 442 DIN
How to order – Article numbers
Type 441, 442 DIN

Type 441 Type 441

Cap H2 Plain lever H3
Closed bonnet Closed bonnet
Conventional design Conventional design

Type 441
Packed lever H4
Closed bonnet
Conventional design

Type 442 Type 441

Plain lever H3 Cap H2
Open bonnet Closed bonnet
Conventional design Balanced bellows design

01/08 LWN 482.01-E

Type 441, 442 DIN
How to order – Article numbers

Type 441, 442 DIN

Article numbers
DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382
Body material: 0.6025 (cast iron)
Bonnet H2 Art.-No. 4411. 4372 – 4382 4392 4402 4412 4422 4432 4442 4452 4462 –
closed H3 Art.-No. 4411. 4373 – 4383 4393 4403 4413 4423 4433 4443 4453 – –
H4 Art.-No. 4411. 4374 – 4384 4394 4404 4414 4424 4434 4444 4454 4464 –
open H3 Art.-No. 4421. 4375 – 4385 4395 4405 4415 4425 4435 4445 4455 4465 –
Body material: 0.7043 (ductile Gr. 60-40-18)
Bonnet H2 Art.-No. 4415. – – 7382 7392 7402 7412 7422 7432 7442 7452 7462 7472
closed H3 Art.-No. 4415. – – 7383 7393 7403 7413 7423 7433 7443 7453 – –
H4 Art.-No. 4415. – – 7384 7394 7404 7414 7424 7434 7444 7454 7464 7474
open H3 Art.-No. 4425. – – 7385 7395 7405 7415 7425 7435 7445 7455 7465 7475
Body material: 1.0619 (WCB)
Bonnet H2 Art.-No. 4412. – 4502 4512 4522 4532 4542 4552 4562 4572 4582 4592 4612
closed H3 Art.-No. 4412. – 4503 4513 4523 4533 4543 4553 4563 4573 4583 – –
H4 Art.-No. 4412. – 4504 4514 4524 4534 4544 4554 4564 4574 4584 4594 4614
open H3 Art.-No. 4422. – 4505 4515 4525 4535 4545 4555 4565 4575 4585 4595 4615
Body material: 1.4408 (CF8M)
Bonnet H2 Art.-No. 4414. – – 4642 4652 4662 4672 4682 4692 4702 4712 4722 –
closed H4 Art.-No. 4414. – – 4644 4654 4664 4674 4684 4694 4704 4714 4724 –

LWN 482.01-E 01/09

 Type 441, 442 DIN
Dimensions and weights

Metric Units
Type 441, 442 DIN

DNI 20 20 25 32 40 50 65 80 100 125 150 200

DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382

Weight 9 9 9 12 16 22 32 56 75 85 131 285

[kg] with bellows 9,4 9,4 10 13 17 24 36 60 83 93 142 289
Center to face Inlet a 85 85 105 115 140 150 170 195 220 250 285 290
[mm] Outlet b 95 95 100 110 115 120 140 160 180 200 225 300
Height (H4) Standard H max. 304 304 339 446 512 569 699 801 883 913 1083 1380
[mm] Bellows H max. 337 337 378 488 550 615 769 860 939 969 1141 1380
Support brackets A 277 277 320 490
[mm] B 160 160 185 1)

(drilled only on request) C Ø 18 Ø 18 Ø 18 Ø 18

D 293 318 392 1)

E 21 21 28 1)

Body material: 0.6025 (cast iron)

DIN Flange2) Inlet PN 16 – PN 16
Outlet PN 16 – PN 16
Body material: 0.7043 (ductile Gr. 60-40-18)
DIN Flange2) Inlet – – PN 40 PN 16 PN 25
Outlet – – PN 16 PN 10
Body material: 1.0619 (WCB)
DIN Flange2) Inlet – PN 40 PN 25
Outlet – PN 16
Body material: 1.4408 (CF8M)
DIN Flange2) Inlet – – PN 40
Outlet – – PN 16
1) 2)
Body B D E Standard flange rating. For other flange drillings and facings please refer to page 01/16 and 01/17.
material [mm] [mm] [mm]

0.6025 150 290 16

0.7043 150 489 25
1.0619 160 489 25
1.4408 150 489 25

Conventional design Support brackets Balanced bellows design

01/10 LWN 482.01-E

Type 441, 442 DIN
Dimensions and weights

US Units

Type 441, 442 DIN

DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [inch] 0.71 0.71 0.91 1.14 1.46 1.81 2.36 2.91 3.62 3.86 4.92 6.5
Actual Orifice area A0 [inch2] 0.394 0.394 0.644 1.024 1.667 2.576 4.383 6.666 10.304 11.691 19.021 33.142

Weight 20 20 20 26 35 49 71 123 165 187 289 628

[lbs] with bellows 21 21 21 28 38 52 79 132 183 205 313 637
Center to face Inlet a 3 11/32 3 11/32 4 1/8 4 17/32 5 16/32 5 29/32 6 11/16 7 11/16 8 21/32 9 27/32 11 7/32 11 13/32
[inch] Outlet b 3 3/ 3 3/ 3 15/ 4 11/ 4 17/ 14 23/ 5 16/ 6 5/ 7 3/ 7 7/ 8 27/32 11 13/16
4 4 16 32 32 32 32 16 32 8

Height (H4) Standard H max. 11 13/16 11 13/16 13 11/32 17 9/16 20 5/32 22 13/32 27 17/32 31 17/32 34 3/4 35 15/16 42 5/8 54 11/32
[inch] Bellows H max. 13 9/ 13 9/ 14 7/ 19 7/ 21 21/ 24 7/ 30 9/ 33 27/ 36 31/ 38 5/ 45 54 11/32
32 32 8 32 32 32 32 32 32 32

Support brackets A 10 29/ 10 29/ 12 19/ 19 19/32

32 32 32
[inch] B 6 1/ 6 1/ 7 9/ 1)
4 4 32

(drilled only on request) C Ø 3/4 Ø 3/4 Ø 3/4 Ø 3/4

D 11 17/32 12 17/32 15 7/16 1)

E 26/ 26/ 1 3/ 1)
32 32 32

Body material: 0.6025 (cast iron)

DIN Flange2) Inlet PN 16 – PN 16
Outlet PN 16 – PN 16
Body material: 0.7043 (ductile Gr. 60-40-18)
DIN Flange2) Inlet – – PN 40 PN 16 PN 25
Outlet – – PN 16 PN 10
Body material: 1.0619 (WCB)
DIN Flange2) Inlet – PN 40 PN 25
Outlet – PN 16
Body material: 1.4408 (CF8M)
DIN Flange2) Inlet – – PN 40
Outlet – – PN 16
1) 2)
Body B D E Standard flange rating. For other flange drillings and facings please refer to page 01/16 and 01/17.
material [inch] [inch] [inch]
29/ 13/ 5/
0.6025 5 32 11 32 8
29/ 17/ 13/
0.7043 5 32 11 32 16

1.0619 6 1/4 11 17/

32
13/
16

29/ 17/ 13/

1.4408 5 32 11 32 16

Conventional design Support brackets Balanced bellows design

LWN 482.01-E 01/11

 Type 441, 442 DIN
Pressure temperature ratings
Type 441, 442 DIN

Metric Units
DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382
Body material: 0.6025 (cast iron)
DIN Flange Inlet PN 16 – PN 16 –
Outlet PN 16 – PN 16 –
Minimum
set pressure p [barg] S/G/L 0.1 – 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 –

Min. set pressure1)

standard bellows p [barg] S/G/L 3 – 3 3 3 3 3 3 2.74 2.01 0.2 –

Min. set pressure

low press. bellows p [barg] S/G/L 2.00 – 0.98 1.41 1.11 1.81 1.50 1.05 1.18 1.41 – –

Maximum
set pressure p [barg] S/G/L 16 – 16 16 16 16 16 16 16 16 16 –

Max. set pressure

with special spring p [barg] S/G/L 16 – 16 16 16 16 16 16 16 16 16 –

Temperature min. [°C] -10 – -10 –

acc. to DIN EN max. [°C] +300 – +300 –
Temperature min. [°C] – – – –
acc. to ASME max. [°C] – – – –

Body material: 0.7043 (ductile Gr. 60-40-18)

DIN Flange Inlet – – PN 40 PN 16 PN 25
Outlet – – PN 16 PN 10
Minimum
set pressure p [barg] S/G/L – – 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

Min. set pressure1)

standard bellows p [barg] S/G/L – – 3 3 3 3 3 3 2.74 2.01 0.2 0.2

Min. set pressure

low press. bellows p [barg] S/G/L – – 0.98 1.41 1.11 1.81 1.50 1.05 1.18 1.41 – –

Maximum
set pressure p [barg] S/G/L – – 40 40 40 40 40 32 40 16 16 20

Max. set pressure

with special spring p [barg] S/G/L – – 40 40 40 40 40 40 40 16 16 25

Temperature min. [°C] – – -60

acc. to DIN EN max. [°C] – – +350
Temperature min. [°C] – – -10
acc. to ASME max. [°C] – – +350
1) Min. set pressure standard bellows = Max. set pressure low pressure bellows.

01/12 LWN 482.01-E

Type 441, 442 DIN
Pressure temperature ratings

Type 441, 442 DIN

Metric Units
DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382
Body material: 1.0619 (WCB)
DIN Flange Inlet – PN 40 PN 25
Outlet – PN 16
Minimum
set pressure p [barg] S/G/L – 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

Min. set pressure1)

standard bellows p [barg] S/G/L – 3 3 3 3 3 3 3 2.74 2.01 0.2 0.2

Min. set pressure

low press. bellows p [barg] S/G/L – 2.00 0.98 1.41 1.11 1.81 1.50 1.05 1.18 1.41 – –

Maximum
set pressure p [barg] S/G/L – 40 40 40 40 40 40 32 40 28 17 20

Max. set pressure

with special spring p [barg] S/G/L – 40 40 40 40 40 40 40 40 28 25 25

Temperature min. [°C] – -85

acc. to DIN EN max. [°C] – +450
Temperature min. [°C] – -29
acc. to ASME max. [°C] – +427

Body material: 1.4408 (CF8M)

DIN Flange Inlet – – PN 40 –
Outlet – – PN 16 –
Minimum
set pressure p [barg] S/G/L – – 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 –

Min. set pressure1)

standard bellows p [barg] S/G/L – – 3 3 3 3 3 3 2.74 2.01 0.2 –

Min. set pressure

low press. bellows p [barg] S/G/L – – 0.98 1.41 1.11 1.81 1.50 1.05 1.18 1.41 – –

Maximum
set pressure p [barg] S/G/L – – 40 40 40 33 28 13.6 20 17.7 7 –

Max. set pressure

with special spring p [barg] S/G/L – – 40 40 40 37 28 25 26 24 10 –

Temperature min. [°C] – – -270 –

acc. to DIN EN max. [°C] – – +400 –
Temperature min. [°C] – – -268 –
acc. to ASME max. [°C] – – +538 –
1) Min. set pressure standard bellows = Max. set pressure low pressure bellows.

LWN 482.01-E 01/13

 Type 441, 442 DIN
Pressure temperature ratings
Type 441, 442 DIN

US Units
DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [inch] 0.71 0.71 0.91 1.14 1.46 1.81 2.36 2.91 3.62 3.86 4.92 6.5
Actual Orifice area A0 [inch2] 0.394 0.394 0.644 1.024 1.667 2.576 4.383 6.666 10.304 11.691 19.021 33.142
Body material: 0.6025 (cast iron)
DIN Flange Inlet PN 16 – PN 16 –
Outlet PN 16 – PN 16 –
Minimum
set pressure p [psig] S/GL 1.5 – 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 –

Min. set pressure1)

standard bellows p [psig] S/GL 43.5 – 43.5 43.5 43.5 43.5 43.5 43.5 39.7 29.1 2.9 –

Min. set pressure

low press. bellows p [psig] S/GL 29 – 14 20 16 26 22 15 17 20 – –

Maximum
set pressure p [psig] S/GL 232 – 232 232 232 232 232 232 232 232 232 –

Max. set pressure

with special spring p [psig] S/GL 232 – 232 232 232 232 232 232 232 232 232 –

Temperature min. [°F] +14 – +14 –

acc. to DIN EN max. [°F] +572 – +572 –
Temperature min. [°F] – – – –
acc. to ASME max. [°F] – – – –

Body material: 0.7043 (ductile Gr. 60-40-18)

DIN Flange Inlet – – PN 40 PN 16 PN 25
Outlet – – PN 16 PN 10
Minimum
set pressure p [psig] S/GL – – 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

Min. set pressure1)

standard bellows p [psig] S/GL – – 43.5 43.5 43.5 43.5 43.5 43.5 39.7 29.1 2.9 2.9

Min. set pressure

low press. bellows p [psig] S/GL – – 14 20 16 26 22 15 17 20 – –

Maximum
set pressure p [psig] S/GL – – 580 580 580 580 580 464 580 232 232 290

Max. set pressure

with special spring p [psig] S/GL – – 580 580 580 580 580 580 580 232 232 363

Temperature min. [°F] – – -76

acc. to DIN EN max. [°F] – – +662
Temperature min. [°F] – – +14
acc. to ASME max. [°F] – – +662
1) Min. set pressure standard bellows = Max. set pressure low pressure bellows.

01/14 LWN 482.01-E

Type 441, 442 DIN
Pressure temperature ratings

Type 441, 442 DIN

US Units
DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [inch] 0.71 0.71 0.91 1.14 1.46 1.81 2.36 2.91 3.62 3.86 4.92 6.5
Actual Orifice area A0 [inch2] 0.394 0.394 0.644 1.024 1.667 2.576 4.383 6.666 1.304 11.691 19.021 33.142
Body material: 1.0619 (WCB)
DIN Flange Inlet – PN 40 PN 25
Outlet – PN 16
Minimum
set pressure p [psig] S/GL – 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

Min. set pressure1)

standard bellows p [psig] S/GL – 43.5 43.5 43.5 43.5 43.5 43.5 43.5 39.7 29.1 2.9 2.9

Min. set pressure

low press. bellows p [psig] S/GL – 29 14 20 16 26 22 15 17 20 – –

Maximum
set pressure p [psig] S/GL – 580 580 580 580 580 580 464 580 406 247 290

Max. set pressure

with special spring p [psig] S/GL – 580 580 580 580 580 580 580 580 406 363 363

Temperature min. [°F] – -121

acc. to DIN EN max. [°F] – +842
Temperature min. [°F] – -20
acc. to ASME max. [°F] – +800

Body material: 1.4408 (CF8M)

DIN Flange Inlet – – PN 40 –
Outlet – – PN 16 –
Minimum
set pressure p [psig] S/GL – – 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 –

Min. set pressure1)

standard bellows p [psig] S/GL – – 43.5 43.5 43.5 43.5 43.5 43.5 39.7 29.1 2.9 –

Min. set pressure

low press. bellows p [psig] S/GL – – 14 20 16 26 22 15 17 20 – –

Maximum
set pressure p [psig] S/GL – – 580 580 580 479 406 197 290 257 102 –

Max. set pressure

with special spring p [psig] S/GL – – 580 580 580 537 406 363 377 348 145 –

Temperature min. [°F] – – -454 –

acc. to DIN EN max. [°F] – – +752 –
Temperature min. [°F] – – -450 –
acc. to ASME max. [°F] – – +1000 –
1) Min. set pressure standard bellows = Max. set pressure low pressure bellows.

LWN 482.01-E 01/15

 Type 441, 442 DIN
Flange drillings
Type 441, 442 DIN

Flange drillings
DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
1 1
– 4" x 1 /2" 1" x 1 /2" 1 /4" x 2" 1 /2" x 2 /2" x 4"
3/ 1 1 1 2" x 3" 3" x 5" 4" x 6" 5" x 8" 6" x 10" 8" x 12"
Valve size 21/2"

Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165

Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382
Body material: 0.6025 (cast iron)
PN 10
* * * * * * * * * *
PN 16
Inlet DIN EN 1092 * * * * * * * * * *
body material 1.0619

Please select other

PN 25 – – – – – – – – – –

body material
Please select

PN 40 – – – – – – – – – –
PN 10 H50 H50
* * * * * * * *
PN 16
Outlet DIN EN 1092 * * * * * * * * * *
PN 25 – – – – – – – – – –
PN 40 – – – – – – – – – –
Body material: 0.7043 (ductile Gr. 60-40-18)
PN 10 H45 H45 H44
* * * * * * *
PN 16 H45
Inlet DIN EN 1092 * * * * * * * * *
Please select other

PN 25 – –
* * * * * * * *
body material

PN 40 * * * * * * * – – –
PN 10 H50 H50
* * * * * * * *
PN 16 (H51)
Outlet DIN EN 1092 * * * * * * * * *
PN 25 ( ) (H15) ( ) – – – – – –
* * *
PN 40 ( ) (H15) ( ) – – – – – –
* * *
Body material: 1.0619 (WCB), 1.4408 (CF8M)
PN 10 H45 H45 H45 H45 H45 H44
* * * * *
PN 16 H45 H45 H45 H45 H45 H44
DIN EN 1092 * * * * *
PN 25
Inlet * * * * * * * * * * *
PN 40
* * * * * * * * * * *
Please select other

CL150 H64 H64 H64 H64 H64 H64 H64 [H64] H64 H64 H64
body material

ASME B16.51)
CL300 – – H65 – [H65] – – – – – –
PN 10 H50 H50 H50
* * * * * * * *
PN 16
DIN EN 1092 * * * * * * * * * * *
PN 25 (H15) ( ) – – – – – H52
Outlet * * * *
PN 40 (H15) ( ) – – – – – H52
* * * *
CL150 H79 H79 H79 H79 H79 [H79] H79 H79 H79 H79 H79
ASME B16.51)
CL300 – – [H80] – – – – – – – –

For signs and symbols refer to page 00/07

Note: Flange drillings and facings meet always the requirements of mentioned flange standards.
Flange thickness and outer diameter may vary from flange standard.

1) For drillings according to ASME B16.5 please use preferred Type 441, 442 ANSI.

01/16 LWN 482.01-E

Type 441, 442 DIN
Flange facings

Type 441, 442 DIN

Flange facings
Indication Standard Inlet Outlet Remark
General
Flange undrilled – H38 H39
Linde-V-Nut, Form V48 Linde Standard 420-08 J07 J08 Groove: Rz 16
Linde-V-Nut, Form V48A LWN 313.36 J05 J06 Groove: Rz 4, e.g. with hydrogen
Lens seal form L DIN 2696
J11 J12
(without sealing lens) LWN 313.35
Acc. to DIN EN 1092
Inlet Outlet Remark
Flange facing Rz-data according to
PN 10 – PN 40 PN 10 – PN 40
(see also LWN 313.40) DIN EN 1092 in μm
Type B1 * * Facing: Rz = 12.5 – 50
Raised face
Type B2 L36 L38 Facing: Rz = 3.2 – 12.5
Tongue face C1) H94 H92

Steel flanges only

Groove face D1) H93 H91
Male face E H96 H98
Female face F H97 H99
O-ring male face G J01 J02
O-ring female face H J03 J04
Acc. to ASME B16.5
Smooth Serrated
RTJ-groove
Finish2) Finish
Body material Inlet Outlet
Inlet Outlet Inlet Outlet Inlet Outlet
Option code Option code RTJ-Class Option code RTJ-Class Option code

1.0619, 1.4408 all all L52 L53 * * CL150 H62 CL150 H63

1) LESER manufactures the groove at flanged valves by milling. If a customer demands a turned surface in the soil of the groove according to DIN EN 1092-1
an additional option code is necessary: “S01: soil of the groove drilled”.
2) Smooth finish is not defined in the effective standards.

For signs and symbols refer to page 00/07

Note: Flange drillings and facings meet always the requirements of mentioned flange standards.
Flange thickness and outer diameter may vary from flange standard.

LWN 482.01-E 01/17

 Type 441, 442 DIN
Order information – Spare parts
Type 441, 442 DIN

Spare parts
DNI 20 20 25 32 40 50 65
DNO 32 40 40 50 65 80 100
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827
Disc (Item 7): Metal to metal seat Material-No. / Art.-No.
Disc 1.4122 210.7039.9000 210.9739.9000 210.9839.9000 210.9939.9000 210.8739.9000 220.1639.9000
detachable lifting aid 1.4404 – 210.9749.9000 210.9849.9000 210.9949.9000 210.8749.9000 220.1649.9000
Disc (Item 7): Soft seal Material-No. / Art.-No.
Disc CR “K” 200.4939.9051 200.5049.9051 200.5149.9051 200.5249.9051 200.5349.9051 200.5449.9051
EPDM “D” 200.4939.9041 200.5049.9041 200.5149.9041 200.5249.9041 200.5349.9041 200.5449.9041
FKM “L” 200.4939.9071 200.5049.9071 200.5149.9071 200.5249.9071 200.5349.9071 200.5449.9071
FFKM “C” 200.4939.9091 200.5049.9091 200.5149.9091 200.5249.9091 200.5349.9091 on request
O-ring (Item 7.4): Soft seal Material-No. / Art.-No.
O-ring CR “K” 502.0171.2651 502.0249.3551 502.0313.3551 502.0408.3551 502.0503.3551 502.0660.5351
EPDM “D” 502.0171.2641 502.0249.3541 502.0313.3541 502.0408.3541 502.0503.3541 502.0660.5341
FKM “L” 502.0171.2671 502.0249.3571 502.0313.3571 502.0408.3571 502.0503.3571 502.0660.5371
FFKM “C” 502.0171.2691 502.0249.3591 502.0313.3591 502.0408.3591 502.0503.3591 on request
Bellows (Item 15): 1.4571 Material-No. / Art.-No.
Standard bellows 400.0149.0000 400.0949.0000 400.1049.0000 400.1149.0000 400.1249.0000 400.1349.0000
Conversion kit standard1) 5021.1040 5021.1041 5021.1042 5021.1043 5021.1044 5021.1045
Low pressure bellows 400.0149.0021 400.0949.0021 400.1049.0021 400.1149.0021 400.1249.0021 400.1349.0021
Conversion kit low pressure1) please specify in writing
Gasket – Body / bonnet (Item 60) Material-No. / Art.-No.
Gasket Graphite + 1.4401 500.0407.0000 500.0607.0000 500.0807.0000 500.1007.0000 500.1207.0000 500.1607.0000
Option code L68 Gylon (filled PTFE) 500.0405.0000 500.0605.0000 500.0805.0000 500.1005.0000 500.1205.0000 500.1605.0000
Ball (Item 61) Material-No. / Art.-No.
Ball Ball Ø [mm] 6 6 6 9 9 12
1.4404 510.0104.0000 510.0104.0000 510.0104.0000 510.0204.0000 510.0204.0000 510.0304.0000
Split ring (Item 14) Material-No. / Art.-No.
Split ring Spindle Ø [mm] 12 12 16 16 16 20
1.4404 251.0149.0000 251.0149.0000 251.0249.0000 251.0249.0000 251.0249.0000 251.0349.0000
Pin (Item 57) Material-No. / Art.-No.
Pin 1.4310 480.0505.0000 480.0505.0000 480.0705.0000 480.0705.0000 480.0705.0000 480.1005.0000

1) For pressure range see page 01/12 – 01/15.

A conversion kit contains the following components:

Item Component No.

8 Guide 1
11 Bonnet spacer 1
12 Spindle 1
15 Bellows 1
55 Stud 4
60 Gasket 3
Installation instruction LWN 037.05 1

Refer to page 01/04

01/18 LWN 482.01-E

Type 441, 442 DIN
Order information – Spare parts

Type 441, 442 DIN

Spare parts
DNI 80 100 125 150 200
DNO 125 150 200 250 300
Actual Orifice diameter d0 [mm] 74 92 98 125 165
Actual Orifice area A0 [mm2] 4301 6648 7543 12272 21382
Disc (Item 7): Metal to metal seat Material-No. / Art.-No.
Disc 1.4122 220.1739.9000 220.1839.9000 220.0439.9000 220.1949.9000 –
detachable lifting aid 1.4404 220.1749.9000 220.1849.9000 220.0449.9000 220.1949.9000 230.1549.9000
Disc (Item 7): Soft seal Material-No. / Art.-No.
Disc CR “K” 200.5549.9051 on request on request on request –
EPDM “D” 200.5549.9041 200.5649.9041 200.5749.9041 200.5849.9041 –
FKM “L” 200.5549.9071 200.5649.9071 200.5749.9071 on request –
FFKM “C” on request on request on request on request –
O-ring (Item 7.4): Soft seal Material-No. / Art.-No.
O-ring CR “K” 502.0819.5351 on request on request on request –
EPDM “D” 502.0819.5341 502.1041.5341 502.1041.5341 502.1295.5341 –
FKM “L” 502.0819.5371 502.1041.5371 502.1041.5371 on request –
FFKM “C” on request on request on request on request –
Bellows (Item 15): 1.4571 Material-No. / Art.-No.
Standard bellows 400.1449.0000 400.0849.0000 400.0849.0000 400.3949.0000 400.5449.0000
Conversion kit standard1) 5021.1046 5021.1047 5021.1047 5021.1048 single parts
Low pressure bellows 400.1449.0021 400.0849.0021 400.0849.0021 – –
Conversion kit low pressure1) please specify in writing – –
Gasket – Body / bonnet (Item 60) Material-No. / Art.-No.
Gasket Graphite + 1.4401 500.1907.0000 500.2107.0000 500.2107.0000 500.2207.0000 500.2807.0000
Option code L68 Gylon (filled PTFE) 500.1905.0000 500.2105.0000 500.2105.0000 500.2205.0000 500.2805.0000
Ball (Item 61) Material-No. / Art.-No.
Ball Ball Ø [mm] 12 15 15 15 18
1.4404 510.0304.0000 510.0404.0000 510.0404.0000 510.0404.0000 510.0505.0000
Split ring (Item 14) Material-No. / Art.-No.
Split ring Spindle Ø [mm] 24 24 24 30 35
1.4404 251.0449.0000 251.0449.0000 251.0449.0000 251.0549.0000 251.1949.0000
Pin (Item 57) Material-No. / Art.-No.
Pin 1.4310 480.1005.0000 480.1105.0000 480.1105.0000 480.1205.0000 480.1405.0000

1) For pressure range see page 01/12 – 01/15.

A conversion kit contains the following components:

Item Component No.

8 Guide 1
11 Bonnet spacer 1
12 Spindle 1
15 Bellows 1
55 Stud 8, 12 depends on valve size
60 Gasket 2, 3 depends on valve size
Installation instruction LWN 037.05 1

Refer to page 01/04

LWN 482.01-E 01/19

 Type 441, 442 DIN
Available Options For further information refer to
“Accessories and Options”, page 99/01
Type 441, 442 DIN

Heating jacket Drain hole Open bonnet

H29, H30: Couplings G 3/8, G 3/4 J18: G 1/4 See Art.-No.
H31, H32: Flanges DN 15, DN 25 J19: G 1/2

O-ring-disc Disc with inserted sealing plate Stainless steel bellows Conversion kit for
J20: FFKM “C” J44: PTFE-FDA J68: Open bonnet stainless steel bellows
J21: CR “K” J48: PCTFE J78: Closed bonnet See Art.-No. page 06/15
J22: EPDM “D” J49: SP
J23: FKM “L”

Screwed cap H2 Plain lever H3 Packed lever H4

H2 H3 H4

Test gag Lift indicator O-ring-damper H2 O-ring-damper H4

J69: H4 J39: Adaptor H4 J65 J66
J70: H2 J93: Lift indicator

01/20 LWN 482.01-E

Type 441, 442 DIN
Approvals

Type 441, 442 DIN

Approvals
DNI 20 – 200
DNO 32 – 300
Actual Orifice diameter d0 [mm] 18 – 165
Actual Orifice area A0 [mm2] 254 – 21382
Europe Coefficient of discharge Kdr
PED/DIN EN ISO 4126-1 Approval No. 072020111Z0008/0/08 Rev.3
S/G 0.7
L 0.45
Germany Coefficient of discharge α w
PED/AD 2000-Merkblatt A2 Approval No. TÜV SV 576
S/G 0.7
L 0.45
United States Coefficient of discharge K
ASME Sec. VIII Div. 1 Approval No. M37044
S/G 0.699
Approval No. M37055
L 0.521
Canada Coefficient of discharge K
Canada: CRN Approval No. For current approval no. see www.leser.com
S/G 0.699
L 0.521
China Coefficient of discharge α w
AQSIQ Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Russia Coefficient of discharge α w
GOST R / RTN Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Kazakhstan Coefficient of discharge α w
GOST-K Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Belarus Coefficient of discharge α w
GOSPROMNAZADOR Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Classification societies Homepage
Bureau Veritas BV www.bureauveritas.com
The valid certification number is changed
Det Norske Veritas DNV www.dnv.com with every renewal.
Germanischer Lloyd GL www.gl-group.com
Lloyd‘ s Register EMEA LREMEA www.lr.org For a sample certificate including the valid
certification number see www.leser.com
Registro Italiano Navale RINA www.rina.org

LWN 482.01-E 01/21

 Type 441, 442 DIN
Capacities – Steam

Capacities for saturated steam according to AD 2000-Merkblatt A2, based on set pressure plus 10 % overpressure.
Type 441, 442 DIN

Capacities at 1 bar (14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [kg/h]

DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382
LEOS/G*) [inch2] 0.283 0.283 0.462 0.734 1.195 1.847 3.142 4.779 7.387 8.382 13.637 23.761
Set pressure [bar] Capacities [kg/h]
0.1 0 0 0 0 0 0 0 0 0 0 0 0
0.2 86 86 140 223 363 561 954 1451 2243 2545 4140 7214
0.5 137 137 224 356 579 895 1523 2316 3580 4062 6609 11516
1 199 199 326 518 843 1302 2215 3370 5209 5910 9616 16755
2 318 318 519 825 1343 2075 3531 5371 8302 9420 15326 26704
3 428 428 699 1111 1808 2794 4754 7232 11178 12683 20635 35954
4 534 534 871 1385 2254 3485 5928 9018 13938 15816 25731 44834
5 639 639 1043 1658 2699 4172 7097 10796 16687 18934 30804 53673
6 744 744 1214 1930 3142 4856 8262 12568 19426 22042 35861 62484
7 846 846 1381 2196 3574 5525 9399 14297 22098 25074 40794 71080
8 950 950 1551 2466 4014 6205 10556 16057 24818 28161 45816 79830
9 1054 1054 1721 2736 4454 6884 11712 17815 27535 31244 50831 88569
10 1158 1158 1891 3006 4893 7562 12866 19571 30250 34324 55842 97300
12 1366 1366 2230 3545 5770 8919 15174 23081 35675 40480 65858 114751
14 1569 1569 2562 4073 6629 10247 17433 26518 40987 46507 75664 131837
16 1776 1776 2900 4610 7505 11600 19735 30020 46400 52650 85657 149249
18 1984 1984 3239 5149 8382 12955 22041 33526 51820 58800 95663 166683
20 2191 2191 3578 5688 9260 14312 24350 37039 57249 64960 105685 184145
22 2393 2393 3907 6212 10111 15629 26590 40446 62515 70935 115407 201085
24 2601 2601 4247 6752 10991 16988 28903 43964 67953 77106 125445 218576
26 2810 2810 4588 7294 11873 18351 31222 47491 73405 83292
28 3019 3019 4930 7837 12757 19718 33547 51029 78873 89496
30 3229 3229 5272 8382 13644 21089 35880 54577 84358
32 3440 3440 5616 8929 14534 22465 38220 58137 89860
34 3641 3641 5945 9451 15384 23779 40455 61537 95115
36 3853 3853 6290 10000 16278 25160 42806 65112 100641
38 4065 4065 6637 10551 17175 26547 45165 68701 106188
40 4278 4278 6985 11104 18076 27939 47533 72303 111756

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

01/22 LWN 482.01-E

Type 441, 442 DIN
Capacities – Steam

Capacities for saturated steam according to ASME Section VIII (UV), based on set pressure plus 10% overpressure.

Type 441, 442 DIN

Capacities at 2.07 bar (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

US Units ASME Section VIII [lb/ h]

DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [inch] 0.71 0.71 0.91 1.14 1.46 1.81 2.36 2.91 3.62 3.86 4.92 6.5
Actual Orifice area A0 [inch2] 0.394 0.394 0.644 1.024 1.667 2.576 4.383 6.666 10.304 11.691 19.021 33.142
LEOS/G*) [inch2] 0.283 0.283 0.462 0.734 1.195 1.847 3.142 4.779 7.387 8.382 13.637 23.761
Set pressure [psig] Capacities [Ib/h]
15 757 1204 1959 3028 5152 7837 12113 13744 22361 38962
20 873 1388 2259 3492 5941 9037 13968 15849 25785 44928
30 1105 1756 2859 4419 7519 11436 17677 20058 32632 56859
40 1360 2162 3519 5439 9254 14076 21757 24687 40165 69983
50 1615 2567 4179 6459 10989 16716 25837 29317 47697 83107
60 1870 2973 4839 7479 12725 19356 29917 33947 55229 96231
70 2125 3378 5499 8499 14460 21995 33997 38576 62761 109355
80 2380 3783 6159 9519 16196 24635 38078 43206 70293 122479
90 2635 4189 6819 10539 17931 27275 42158 47836 77825 135603
100 2890 4594 7479 11559 19666 29915 46238 52466 85357 148727
120 3400 5405 8799 13600 23137 35194 54398 61725 100422 174975
140 3910 6216 10118 15640 26608 40474 62558 70984 115486 201223
160 4420 7027 11438 17680 30079 45753 70719 80244 130550 227471
180 4930 7838 12758 19720 33550 51033 78879 89503 145615 253719
Please select DNI 25

200 5440 8648 14078 21760 37020 56312 87039 98762 160679 279967
220 5950 9459 15398 23800 40491 61592 95200 108022 175743 306215
240 6460 10270 16718 25840 43962 66871 103360 117281 190808 332463
260 6970 11081 18038 27880 47433 72151 111520 126540 205872 358711
280 7480 11892 19358 29920 50904 77430 119680 135800 220936 384960
300 7990 12703 20677 31960 54375 82710 127841 145059 236001 411208
320 8500 13513 21997 34000 57845 87989 136001 154319 251065 437456
340 9010 14324 23317 36040 61316 93269 144161 163578 266129 463704
360 9520 15135 24637 38080 64787 98548 152321 172837 281194 489952
380 10030 15946 25957 40120 68258 103828 160482 182097
400 10540 16757 27277 42161 71729 109107 168642 191356
420 11050 17567 28597 44201 75199 114387 176802
440 11560 18378 29917 46241 78670 119666 184963
460 12070 19189 31236 48281 82141 124946 193123
480 12580 20000 32556 50321 85612 130225 201283
500 13090 20811 33876 52361 89083 135505 209443
550 14365 22838 37176 57461 97760 148704 229844
580 15130 24054 39156 60521 102966 156623 242085

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

LWN 482.01-E 01/23

 Type 441, 442 DIN
Capacities – Air

Capacities for air according to AD 2000-Merkblatt A2, based on set pressure plus 10 % overpressure at 0 °C and 1013 mbar.
Type 441, 442 DIN

Capacities at 1 bar (14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [mn3/h]

DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382
LEOS/G*) [inch2] 0.283 0.283 0.462 0.734 1.195 1.847 3.142 4.779 7.387 8.382 13.637 23.761
Set pressure [bar] Capacities [mn3/h]
0.1 0 0 0 0 0 0 0 0 0 0 0 0
0.2 99 99 162 258 420 649 1105 1680 2597 2947 4794 8354
0.5 161 161 263 418 680 1051 1789 2721 4206 4772 7764 13528
1 238 238 388 617 1004 1552 2641 4017 6209 7045 11461 19970
2 384 384 627 996 1622 2507 4265 6487 10026 11377 18509 32251
3 523 523 854 1357 2209 3414 5809 8836 13657 15497 25212 43930
4 656 656 1071 1703 2773 4286 7291 11091 17143 19452 31647 55142
5 790 790 1289 2050 3337 5157 8774 13346 20629 23407 38082 66354
6 923 923 1507 2396 3900 6029 10257 15601 24114 27362 44516 77565
7 1057 1057 1725 2742 4464 6900 11739 17857 27600 31317 50951 88777
8 1190 1190 1943 3089 5028 7771 13222 20112 31086 35273 57386 99989
9 1323 1323 2161 3435 5592 8643 14704 22367 34571 39228 63821 111201
10 1457 1457 2379 3781 6155 9514 16187 24622 38057 43183 70255 122413
12 1724 1724 2814 4474 7283 11257 19152 29132 45028 51093 83125 144836
14 1991 1991 3250 5167 8411 13000 22117 33642 52000 59003 95994 167260
16 2257 2257 3686 5859 9538 14743 25082 38153 58971 66914 108863 189684
18 2524 2524 4121 6552 10666 16486 28047 42663 65942 74824 121733 212107
20 2791 2791 4557 7245 11793 18228 31012 47173 72913 82734 134602 234531
22 3058 3058 4993 7938 12921 19971 33977 51683 79885 90644 147472 256954
24 3325 3325 5429 8630 14048 21714 36943 56194 86856 98555 160341 279378
26 3592 3592 5864 9323 15176 23457 39908 60704 93827 106465
28 3859 3859 6300 10016 16304 25200 42873 65214 100799 114375
30 4125 4125 6736 10708 17431 26942 45838 69725 107770
32 4392 4392 7171 11401 18559 28685 48803 74235 114741
34 4659 4659 7607 12094 19686 30428 51768 78745 121713
36 4926 4926 8043 12786 20814 32171 54733 83255 128684
38 5193 5193 8478 13479 21941 33914 57698 87766 135655
40 5460 5460 8914 14172 23069 35657 60663 92276 142626

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

01/24 LWN 482.01-E

Type 441, 442 DIN
Capacities – Air

Capacities for air according to ASME Section VIII (UV), based on set pressure plus 10 % overpressure at 16 °C (60 °F).

Type 441, 442 DIN

Capacities at 2.07 bar (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

US Units ASME Section VIII [lS.C.F.M.]

DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [inch] 0.71 0.71 0.91 1.14 1.46 1.81 2.36 2.91 3.62 3.86 4.92 6.5
Actual Orifice area A0 [inch2] 0.394 0.394 0.644 1.024 1.667 2.576 4.383 6.666 10.304 11.691 19.021 33.142
LEOS/G*) [inch2] 0.283 0.283 0.462 0.734 1.195 1.847 3.142 4.779 7.387 8.382 13.637 23.761
Set pressure [psig] Capacities [S.C.F.M.]
15 270 429 698 1079 1835 2792 4315 4896 7965 2780
20 311 494 805 1244 2116 3219 4976 5646 9185 3142
30 394 626 1019 1574 2679 4074 6297 7145 11624 3764
40 484 770 1254 1938 3297 5014 7750 8794 14307 4346
50 575 915 1489 2301 3915 5954 9204 10444 16990 4859
60 666 1059 1724 2664 4533 6895 10657 12093 19673 5323
70 757 1204 1959 3028 5152 7835 12111 13742 22356 5749
80 848 1348 2194 3391 5770 8775 13564 15391 25039 6146
90 939 1492 2430 3754 6388 9715 15018 17041 27722 6519
100 1029 1637 2665 4118 7006 10656 16471 18690 30406 6872
120 1211 1926 3135 4845 8243 12536 19378 21988 35772 7528
140 1393 2215 3605 5571 9479 14417 22285 25287 41138 8131
160 1574 2504 4076 6298 10716 16298 25192 28585 46504 8692
180 1756 2792 4546 7025 11952 18178 28099 31884 51870 9220
Please select DNI 25

200 1938 3081 5016 7751 13189 20059 31006 35182 57236 9718
220 2120 2120 5486 8478 14425 21939 33913 38481 62602 10193
240 2301 3659 5957 9205 15662 23820 36820 41779 67968 10646
260 2483 3948 16427 9932 16898 25700 39727 45078 73334 11081
280 2665 4237 6897 10658 18135 27581 42633 48376 78701 11499
300 2846 4526 7368 11385 19371 29462 45540 51675 84067 11902
320 3028 4815 7838 12112 20608 31342 48447 54973 89433 12293
340 3210 5104 8308 12839 21844 33223 51354 58272 94799 12671
360 3391 5392 8778 13565 23081 35103 54261 61570 100165 13039
380 3573 5681 9249 14292 24317 36984 57168 64869
400 3755 5970 9719 15019 25554 38864 60075 68167
420 3936 6259 10189 15745 26791 40745 62982
440 4118 6548 110660 16472 28027 42626 65889
460 4300 6837 11130 17199 29264 44506 68796
480 4481 7126 11600 17926 30500 46387 71703
500 4663 7415 12070 18652 31737 48267 74610
550 5117 8137 13246 20469 34828 52969 81877
580 5390 8570 13952 21559 36683 55790 86237

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

LWN 482.01-E 01/25

 Type 441, 442 DIN
Capacities – Water

Capacities for water according to AD 2000-Merkblatt A2, based on set pressure plus 10 % overpressure at 20 °C (68 °F).
Type 441, 442 DIN

Capacities at 1 bar (14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [103kg/h]

DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [mm] 18 18 23 29 37 46 60 74 92 98 125 165
Actual Orifice area A0 [mm2] 254 254 416 661 1075 1662 2827 4301 6648 7543 12272 21382
LEOL*) [inch2] 0.316 0.316 0.516 0.821 1.336 2.062 3.513 5.343 8.259 9.371 15.246 26.565
Set pressure [bar] Capacities [103kg/h]
0.1 2.60 2.60 4.25 6.76 11.0 17.0 28.9 44.0 68.0 77.2 126 219
0.2 3.19 3.19 5.21 8.28 13.5 20.8 35.5 53.9 83.3 94.6 154 268
0.5 4.51 4.51 7.37 11.7 19.1 29.5 50.1 76.3 118 134 218 379
1 6.11 6.11 9.97 15.9 25.8 39.9 67.9 103 160 181 295 513
2 8.64 8.64 14.1 22.4 36.5 56.4 96.0 146 226 256 417 726
3 10.6 10.6 17.3 27.5 44.7 69.1 118 179 276 314 510 889
4 12.2 12.2 19.9 31.7 51.6 79.8 136 206 319 362 589 1027
5 13.7 13.7 22.3 35.5 57.7 89.2 152 231 357 405 659 1148
6 15.0 15.0 24.4 38.8 63.2 97.7 166 253 391 444 722 1257
7 16.2 16.2 26.4 42.0 68.3 106 180 273 422 479 779 1358
8 17.3 17.3 28.2 44.8 73.0 113 192 292 451 512 833 1452
9 18.3 18.3 29.9 47.6 77.4 120 204 310 479 543 884 1540
10 19.3 19.3 31.5 50.1 81.6 126 215 326 505 573 932 1623
12 21.2 21.2 34.6 54.9 89.4 138 235 358 553 627 1021 1778
14 22.9 22.9 37.3 59.3 96.6 149 254 386 597 678 1102 1921
16 24.4 24.4 39.9 63.4 103 160 272 413 638 724 1178 2053
18 25.9 25.9 42.3 67.3 110 169 288 438 677 768 1250 2178
20 27.3 27.3 44.6 70.9 115 178 304 462 714 810 1317 2296
22 28.7 28.7 46.8 74.4 121 187 318 484 748 849 1382 2408
24 29.9 29.9 48.9 77.7 126 195 333 506 782 887 1443 2515
26 31.1 31.1 50.9 80.9 132 203 346 526 814 923
28 32.3 32.3 52.8 83.9 137 211 359 546 844 958
30 33.5 33.5 54.6 86.8 141 219 372 565 874
32 34.6 34.6 56.4 89.7 146 226 384 584 903
34 35.6 35.6 58.2 92.5 151 233 396 602 931
36 36.7 36.7 59.8 95.1 155 239 407 619 957
38 37.7 37.7 61.5 97.7 159 246 418 636 984
40 38.6 38.6 63.1 100 163 252 429 653 1009

*) LEOL = LESER Effective Orifice liquids please refer to page 00/12

How to use capacity-sheets refer to page 00/09

01/26 LWN 482.01-E

Type 441, 442 DIN
Capacities – Water

Capacities for water according to ASME Section VIII (UV), based on set pressure plus 10 % overpressure at 21 °C (70 °F).

Type 441, 442 DIN

Capacities at 2.07 bar (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

US Units ASME Section VIII [US-G.P.M.]

DNI 20 20 25 32 40 50 65 80 100 125 150 200
DNO 32 40 40 50 65 80 100 125 150 200 250 300
Actual Orifice diameter d0 [inch] 0.71 0.71 0.91 1.14 1.46 1.81 2.36 2.91 3.62 3.86 4.92 6.5
Actual Orifice area A0 [inch2] 0.394 0.394 0.644 1.024 1.667 2.576 4.383 6.666 10.304 11.691 19.021 33.142
LEOL*) [inch2] 0.316 0.316 0.516 0.821 1.336 2.062 3.513 5.343 8.259 9.371 15.246 26.565
Set pressure [psig] Capacities [US-G.P.M.]
15 54.0 85.9 140 216 368 559 864 981 1595 2780
20 61.1 97.1 158 244 416 632 977 1109 1803 3142
30 73.1 116 189 293 498 757 1170 1328 2160 3764
40 84.5 134 219 338 575 874 1351 1533 2494 4346
50 94.4 150 244 378 643 977 1511 1714 2789 4859
60 103 164 268 414 704 1071 1655 1878 3055 5323
70 112 178 289 447 760 1156 1787 2028 3300 5749
80 119 190 309 478 813 1236 1911 2168 3527 6146
90 127 201 328 507 862 1311 2027 2300 3741 6519
100 134 212 346 534 909 1382 2136 2424 3944 6872
120 146 233 379 585 996 1514 2340 2656 4320 7528
140 158 251 409 632 1075 1635 2528 2868 4666 8131
160 169 269 437 676 1150 1748 2702 3066 4989 8692
180 179 285 464 717 1219 1854 2866 3252 5291 9220
200 189 300 489 755 1285 1955 3021 3428 5577 9718
220 198 315 513 792 1348 2050 3169 3596 5850 10193
Please select DNI 25

240 207 329 535 827 1408 2141 3310 3756 6110 10646
260 215 342 557 861 1465 2229 3445 3909 6359 11081
280 223 355 578 894 1521 2313 3575 4057 6599 11499
300 231 368 599 925 1574 2394 3700 4199 6831 11902
320 239 380 618 955 1626 2472 3822 4337 7055 12293
340 246 391 637 985 1676 2549 3939 4470 7272 12671
360 253 403 656 1013 1724 2622 4054 4600 7483 13039
380 260 414 674 1041 1772 2694 4165 4726
400 267 425 691 1068 1818 2764 4273 4848
420 274 435 708 1095 1862 2833 4378
440 280 445 725 1120 1906 2899 4481
460 286 455 741 1146 1949 2964 4582
480 293 465 757 1170 1991 3028 4681
500 299 475 773 1194 2032 3091 4777
550 313 498 811 1253 2131 3241 5010
580 322 511 832 1286 2189 3329 5145

*) LEOL = LESER Effective Orifice liquids please refer to page 00/12

How to use capacity-sheets refer to page 00/09

LWN 482.01-E 01/27

 Type 441, 442 DIN
h = Lift [mm]
Determination of coefficent of discharge d0 = Flow diameter [mm] of selected safety
in case of lift restriction or back pressure valve, refer to table article numbers
h/d0 = Ratio of lift / flow diameter
p a0 = Back pressure [bara]
p0 = Set pressure [bara]
pa0 / p0 = Ratio of back pressure / set pressure
Kdr = Coefficient of discharge
Type 441, 442 DIN

acc. to DIN EN ISO 4126-1

αw = Coefficient of discharge
acc. to AD 2000-Merkblatt A2
Kb = Back pressure correction factor
acc. to API 520 topic 3.3
Diagram for evaluation of ratio of lift / flow diameter (h/d0)
in reference to the coefficent of discharge (Kdr / αw) How to use please refer to page 00/08

Kdr = αw = f (h/d0)
0.800

DN 20 – 100 S/G
0.700

DN 200 cast S/G

0.600

DN 125 – 150, S/G

0.500
DN 200 cast L

0.400
Coefficient of discharge Kdr / αw

DN 20 – 100 L
0.300

DN 125 – 150, L
0.200

0.100

0
0 0.050 0.100 0.150 0.200 0.250 0.300
0.21 0.243 0.270
Ratio of lift / flow diameter h / d0

Diagram for evaluation of coefficient of discharge (Kdr / αw) or Kb

in reference to the ratio of back pressure / set pressure (pa0 / p0)

Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0)

0.8

0.7 1.0

0.9
0.6
0.8
0.5 0.7

0.6
Back pressure correction factor Kb

0.4
Coefficient of discharge Kdr / αw

0.5
0.3
0.4

0.2 0.3

0.2
0.1
0.1

0 0
0.2 0.3 0.4 0.5 0.6 0.7 0.8
0.91
Ratio of back pressure / set pressure pa0 / p0

01/28 LWN 482.01-E

 Type
Type 442 ANSI
Plain lever H3
Open bonnet
Conventional design
441 ANSI
442 ANSI

Type 441, 442 ANSI

Flanged Safety Relief Valves
– spring loaded

Contents Chapter/Page
Materials
• Conventional design 02/02
• Balanced bellows design 02/04
How to order
• Numbering system 02/06
• Article numbers 02/08
Dimensions and weights
• Metric Units 02/10
• US Units 02/11
Type 441 ANSI
Packed lever H4 Pressure temperature ratings
Closed bonnet • Metric Units 02/12
Conventional design • US Units 02/13
Flange drillings and facings 02/14
Order information – Spare parts 02/15
Available options 02/16
Approvals 02/17
Capacities
• Steam [Metric Units + US Units] 02/18
• Air [Metric Units + US Units] 02/19
• Water [Metric Units + US Units] 02/20
Determination of coefficient 02/21
of discharge Kdr /α w

LWN 482.01-E 02/01

 Type 441, 442 ANSI
Conventional design

40 Cap H2

18 Adjusting screw
Type 441, 442 ANSI

19 Lock nut

16 Upper spring plate

9 Bonnet

12 Spindle

54 Spring

14 Split ring

55 Stud

56 Nut

17 Lower spring plate

8 Guide with bushing

60 Gasket

57 Pin

61 Ball

7 Disc

5 Seat

1 Body

02/02 LWN 482.01-E

Type 441, 442 ANSI
Conventional design

Materials
Item Component Type 4412 / 4422 ANSI Type 4414 ANSI

1.0619 1.4408
1 Body
SA 216 WCB SA 351 CF8M
1.4404 1.4404
5 Seat
316L 316L

Type 441, 442 ANSI

1.4122 1.4404
7 Disc
Hardened stainless steel 316L
1.4104, 1.0501, 0.7040 1.4404
Guide
Chrome or carbon steel 316L
8
1.4104 tenifer –
with bushing
Chrome steel tenifer –
0.7040, 0.7043, 1.0619 1.4408, 1.4404, 1.4571
9 Bonnet Ductile Gr. 60-40-18, SA 351 CF8M, SA 479 316L,
SA 216 WCB SA 479 316Ti
1.4021 1.4404
12 Spindle
420 316L
1.4104 1.4404
14 Split ring
Chrome steel 316L
1.0718 1.4404
16/17 Spring plate
Steel 316L
Adjusting screw 1.4104 PTFE 1.4404 PTFE
18
with bushing Chrome steel PTFE 316L PTFE
1.0718 1.4404
19 Lock nut
Steel 316L
1.0718 or 0.7043 1.4404
40 Cap H2
12L13 or Gr. 60-40-18 316L
1.1200, 1.8159, 1.7102 1.4310
Spring standard
Carbon steel Stainless steel
54
1.4310 –
Spring optional
Stainless steel –
1.1181 1.4401
55 Stud
Steel B8M
1.0501 1.4401
56 Nut
2H 8M
1.4310 1.4310
57 Pin
Stainless steel Stainless steel
Graphite / 1.4401 Graphite / 1.4401
60 Gasket
Graphite / 316 Graphite / 316
1.3541 1.4401
61 Ball
Hardened stainless steel 316

Please notice:

– Modifications reserved by LESER.

– If several materials are specified LESER defines the material.
– LESER can upgrade materials without notice.
– Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 02/03

 Type 441, 442 ANSI
Balanced bellows design

40 Cap H2

18 Adjusting screw

19 Lock nut

16 Upper spring plate

Type 441, 442 ANSI

9 Bonnet

12 Spindle

54 Spring

14 Split ring

17 Lower spring plate

55 Stud

56 Nut

8 Guide with bushing

60 Gasket

11 Bonnet spacer

60 Gasket

22 Lift stopper
15 Bellows
57 Pin

61 Ball

7 Disc

5 Seat
1 Body

02/04 LWN 482.01-E

Type 441, 442 ANSI
Balanced bellows design

Materials
Item Component Type 4412 / 4422 ANSI Type 4414 ANSI

1.0619 1.4408
1 Body
SA 216 WCB SA 351 CF8M
1.4404 1.4404
5 Seat
316L 316L
1.4122 1.4404
7 Disc
Hardened stainless steel 316L

Type 441, 442 ANSI

1.4104, 1.0501, 0.7040 1.4404
Guide
Chrome or carbon steel 316L
8
1.4104 tenifer –
with bushing
Chrome steel tenifer –
0.7040, 0.7043, 1.0619 1.4408, 1.4404, 1.4571
9 Bonnet Ductile Gr. 60-40-18, SA 351 CF8M, SA 479 316L,
SA 216 WCB SA 479 316Ti
1.4404 1.4404
11 Bonnet spacer
316L 316L
1.4404 1.4404
12 Spindle
316L 316L
1.4104 1.4404
14 Split ring
Chrome steel 316L
1.4571 1.4571
15 Bellows
316Ti 316Ti
1.0718 1.4404
16/17 Spring plate
Steel 316L
Adjusting screw 1.4104 PTFE 1.4404 PTFE
18
with bushing Chrome steel PTFE 316L PTFE
1.0718 1.4404
19 Lock nut
Steel 316L
1.4404 1.4404
22 Lift stopper
316L 316L
1.0718 or 0.7043 1.4404
40 Cap H2
12L13 or Gr. 60-40-18 316L
1.1200, 1.8159, 1.7102 1.4310
Spring standard
Carbon steel Stainless steel
54
1.4310 –
Spring optional
Stainless steel –
1.4401 1.4401
55 Stud
B8M B8M
1.4401 1.4401
56 Nut
8M 8M
1.4310 1.4310
57 Pin
Stainless steel Stainless steel
Graphite / 1.4401 Graphite / 1.4401
60 Gasket
Graphite / 316 Graphite / 316
1.3541 1.3541
61 Ball
Hardened stainless steel 316

Please notice:

– Modifications reserved by LESER.

– If several materials are specified LESER defines the material.
– LESER can upgrade materials without notice.
– Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 02/05

 Type 441, 442 ANSI
How to order – Example for numbering system

1 Article Number
2 Set Pressure
3 Connections
Type 441, 442 ANSI

4412.4812 5 barg H45

Please state unit (in gauge)! Please refer to page 02/14

1 2 3 4
Please do not exceed the pressure
441 2 . 481 2 range defined in the spring charts.

1 Valve Type 441, 442 ANSI

Type 441 – with closed bonnet
Type 442 – with open bonnet

Code Body material

2 1.0619 (WCB)

4 1.4408 (CF8M)

3 Valve code
Identifies valve size and body
material, refer to page 02/09.

Code Lifting lever

2 screwed cap H2
3 plain lever H3
4 packed lever H4
plain lever
5 with open H3
bonnet

02/06 LWN 482.01-E

Type 441, 442 ANSI

4 Options
5 Documentation
6
Code and Medium

Type 441, 442 ANSI

J22 H01 L30 2.0

Type 441, 442 ANSI Option code Please select requested documentation:
1 2

• O-ring-disc Inspections, tests: Option code 2 . 0

CR “K” J21 DIN EN 10204-3.2: TÜV-Nord
EPDM “D” J22 Certificate for test pressure M33 1 Code
FKM “L” J23 1. ASME Section VIII
FFKM “C” J20 LESER CGA (Certificate for H03 2. CE / VdTUEV
Global Application) 3. ASME Section VIII
• Disc 1.4404 / 316L L44
- Inspection certificate 3.1 acc. + CE / VdTUEV
• Disc 1.4404 / 316L stellited J25 to DIN EN 10204
• Detachable lifting aid J26 - Declaration of conformity acc.
• Stainless steel bellows to PED 97/23/EC
2 Medium
- open bonnet (Type 442) J68
.1 Gases
- closed bonnet (Type 441) J78 Material test certificate: .2 Liquids
• Elastomer bellows J79 DIN EN 10204-3.1 .3 Steam
• High temperature alloy spring X01
.0 Steam / Gases / Liquids
• Stainless steel spring X04 Part Option code (valid only for CE / VdTUEV)
• Adaptor for lift indicator H4 J39 Body H01
• Lift indicator J93 Bonnet L30
• Test gag Cap / lever cover L31
- cap H2 J70 Disc L23
- packed lever H4 J69 Studs N07
• Seat 1.4404 / 316L stellited L61 Nuts N08
• Heating jacket
- Couplings G 3/8 H29
G 3/4 H30
- Flanges DN 15 H31
DN 25 H32
• Drain hole G 1/4 J18
G 1/2 J19
• Free of oil and grease J85
• Materials
- NACE N78

Option code applies only

if not standard

LWN 482.01-E 02/07

 Type 441, 442 ANSI
How to order – Article numbers
Type 441, 442 ANSI

Type 441
Cap H2
Closed bonnet
Conventional design

Type 441
Packed lever H4
Closed bonnet
Conventional design

Type 442
Plain lever H3
Open bonnet
Conventional design

02/08 LWN 482.01-E

Type 441, 442 ANSI
How to order – Article numbers

Article numbers
Valve size 1" x 2" 1 1/2" x 2" 1 1/2" x 2 1/2" 2" x 3" 3" x 4 " 4" x 6"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 92
Actual Orifice area A0 [mm2] 416 661 1075 1662 2827 6648
Body material: 1.0619 (WCB)
Bonnet H2 Art.-No. 4412. 4812 4822 4832 4842 4862 4872
closed H3 Art.-No. 4412. 4813 4823 4833 4843 4863 4873

Type 441, 442 ANSI

H4 Art.-No. 4412. 4814 4824 4834 4844 4864 4874
open H3 Art.-No. 4422. 4815 4825 4835 4845 4865 4875
Body material: 1.4408 (CF8M)
Bonnet H2 Art.-No. 4414. 7912 – 7932 7942 7962 7972
closed H4 Art.-No. 4414. 7914 – 7934 7944 7964 7974

LWN 482.01-E 02/09

 Type 441, 442 ANSI
Dimensions and weights

Metric Units
Valve size 1" x 2" 1 1/2" x 2" 1 1/2" x 2 1/2" 2" x 3" 3" x 4" 4" x 6"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 92
Actual Orifice area A0 [mm2] 416 661 1075 1662 2827 6648

Weight 10 13 16 22 33 75
[lbs] with bellows 11 14 17 24 37 83
Type 441, 442 ANSI

Center to face Inlet a 105 124 124 136 156 181

[mm] Outlet b 114 121 121 124 165 229
Height (H4) Standard H max. 339 455 496 556 685 844
[mm] Bellows H max. 378 497 534 602 741 902
Support brackets A 280
[mm] B 160
(drilled only on request) C Ø 18
D 250
E 25

Body material: 1.0619 (WCB)

ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150
Body material: 1.4408 (CF8M)
ANSI Flange Inlet CL150 or CL300 – CL150 or CL300
Class1) Outlet CL150 – CL150

1) Standard flange rating. For other flange drillings and facings please refer to page 02/14.

Conventional design Support brackets Balanced bellows design

02/10 LWN 482.01-E

Type 441, 442 ANSI
Dimensions and weights

US Units
Valve size 1" x 2" 1 1/2" x 2" 1 1/2" x 2 1/2" 2" x 3" 3" x 4 " 4" x 6"
Actual Orifice diameter d0 [inch] 0.91 1.14 1.46 1.81 2.36 3.62
Actual Orifice area A0 [inch2] 0.644 1.024 1.667 2.576 4.383 10.304

Weight 22 29 35 49 73 165
[lbs] with bellows 23 30 38 52 81 183

Type 441, 442 ANSI

Center to face Inlet a 4 1/8 4 7/8 4 7/8 5 3/8 6 1/8 7 1/8
[inch] Outlet b 4 1/2 4 3/4 4 3/4 4 7/8 6 1/2 9
Height (H4) Standard H max. 13 11/32 17 29/32 19 17/32 21 1/16 26 31/32 33 7/32
[inch] Bellows H max. 14 7/8 19 9/16 21 1/32 23 11/16 29 3/16 35 1/2
Support brackets A 11
[inch] B 6 1/4
(drilled only on request) C Ø 3/4
D 9 7/8
E 25

Body material: 1.0619 (WCB)

ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150
Body material: 1.4408 (CF8M)
ANSI Flange Inlet CL150 or CL300 – CL150 or CL300
Class1) Outlet CL150 – CL150

1) Standard flange rating. For other flange drillings and facings please refer to page 02/14.

Conventional design Support brackets Balanced bellows design

LWN 482.01-E 02/11

 Type 441, 442 ANSI
Pressure temperature ratings

Metric Units
Valve size 1" x 2" 11/2" x 2" 11/2" x 21/2" 2 x 3" 3 x 4" 4 x 6"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 92
Actual Orifice area A0 [mm2] 416 661 1075 1662 2827 6648
Body material: 1.0619 (WCB)
ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150
Type 441, 442 ANSI

Minimum
set pressure p [barg] S/G/L 0.1 0.1 0.1 0.1 0.1 0.1

Min. set pressure2)

standard bellows p [barg] S/G/L 3 3 3 3 3 3

Min. set pressure

low press. bellows p [barg] S/G/L 0.98 1.41 1.11 1.81 1.50 1.18

Maximum
set pressure p [barg] S/G/L 49 48 46 51 35 34

Max. set pressure

with special spring p [barg] S/G/L 51 48 46 51 40 34

Temperature3) min. [°C] -85

acc. to DIN EN max. [°C] +450
Temperature3) min. [°C] -29
acc. to ASME max. [°C] +427

Body material: 1.4408 (CF8M)

ANSI Flange Inlet CL150 or CL 300 – CL150 or CL300
Class1) Outlet CL150 – CL150
Minimum
set pressure p [barg] S/G/L 0.1 – 0.1 0.1 0.1 0.1

Min. set pressure2)

standard bellows p [barg] S/G/L 3 – 3 3 3 3

Min. set pressure

low press. bellows p [barg] S/G/L 0.98 – 1.11 1.81 1.50 1.18

Maximum
set pressure p [barg] S/G/L 42.5 – 40 32 27 20

Max. set pressure

with special spring p [barg] S/G/L 51 – 40 40 27 25

Temperature3) min. [°C] -270 – -270

acc. to DIN EN max. [°C] +400 – +400
Temperature3) min. [°C] -268 – -268
acc. to ASME max. [°C] +538 – +538

1) For flange rating class 150 the pressure temperature ratings according to ASME ANSI B 16.34 apply.
2) Min. set pressure standard bellows = Max. set pressure low pressure bellows.
3) Between -10 °C and lowest temperature indicated „AD 2000-Merkblatt“ W10 shall be taken into account.

02/12 LWN 482.01-E

Type 441, 442 ANSI
Pressure temperature ratings

US Units
Valve size 1" x 2" 11/2" x 2" 11/2" x 21/2" 2 x 3" 3 x 4" 4 x 6"
Actual Orifice diameter d0 [inch] 0.91 1.14 1.46 1.81 2.36 3.62
Actual Orifice area A0 [inch2] 0.644 1.024 1.667 2.576 4.383 1.304
Body material: 1.0619 (WCB)
ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150

Type 441, 442 ANSI

Minimum
set pressure p [psig] S/G/L 1.5 1.5 1.5 1.5 1.5 1.5

Min. set pressure2)

standard bellows p [psig] S/G/L 43.5 43.5 43.5 43.5 43.5 43.5

Min. set pressure

low press. bellows p [psig] S/G/L 14 20 16 26 22 17

Maximum
set pressure p [psig] S/G/L 711 696 667 740 508 493

Max. set pressure

with special spring p [psig] S/G/L 740 696 667 740 580 493

Temperature3) min. [°F] -121

acc. to DIN EN max. [°F] +842
Temperature3) min. [°F] -20
acc. to ASME max. [°F] +800

Body material: 1.4408 (CF8M)

ANSI Flange Inlet CL150 or CL300 – CL150 or C300
Class1) Outlet CL150 – CL150
Minimum
set pressure p [psig] S/G/L 1.5 – 1.5 1.5 1.5 1.5

Min. set pressure2)

standard bellows p [psig] S/G/L 43.5 – 43.5 43.5 43.5 43.5

Min. set pressure

low press. bellows p [psig] S/G/L 14 – 16 26 22 17

Maximum
set pressure p [psig] S/G/L 616 – 580 464 392 290

Max. set pressure

with special spring p [psig] S/G/L 740 – 580 580 392 363

Temperature3) min. [°F] -454 – -454

acc. to DIN EN max. [°F] +752 – +752
Temperature3) min. [°F] -450 – -450
acc. to ASME max. [°F] +1000 – +1000

1) For flange rating class 150 the pressure temperature ratings according to ASME ANSI B 16.34 apply.
2) Min. set pressure standard bellows = Max. set pressure low pressure bellows.
3) Between -10 °C and lowest temperature indicated „AD 2000-Merkblatt“ W10 shall be taken into account.

LWN 482.01-E 02/13

 Type 441, 442 ANSI
Flange drillings and facings

Flange drillings
Valve size 1" x 2" 11/2" x 2" 11/2" x 21/2" 2" x 3" 3" x 4" 4" x 6"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 92
Actual Orifice area A0 [mm2] 416 661 1075 1662 2827 6648
Gehäusewerkstoff: 0.6025 (Grauguss)
CL150 H64 H64 H64 H64 H64 H64
Inlet ASME B16.5
CL300
* * * * * *
Type 441, 442 ANSI

CL150
Outlet ASME B16.5 * * * * * *
CL300 – – – – – –

Flange facings
Indication Standard Inlet Outlet Remark
General
Flange undrilled – H38 H39
Linde-V-Nut, Form V48 Linde Standard 420-08 J07 J08 Groove: Rz 16
Linde-V-Nut, Form V48A LWN 313.36 J05 J06 Groove: Rz 4, e.g. with hydrogen
Lens seal form L DIN 2696
J11 J12
(without sealing lens) LWN 313.35
Acc. to DIN EN 1092
Inlet Outlet Remark
Flange facing Rz-data according to
PN 10 – PN 40 PN 10 – PN 40
(see also LWN 313.40) DIN EN 1092 in μm
Type B1 Facing: Rz = 12.5 – 50
Raised face * *
Type B2 L36 L38 Facing: Rz = 3.2 – 12.5
Tongue face C1) H94 H92
Groove face D1) H93 H91 Steel flanges only

Male face E H96 H98

Female face F H97 H99
O-ring male face G J01 J02
O-ring female face H J03 J04
Acc. to ASME B16.5
Smooth Serrated
RTJ-groove
Finish2) Finish
Body material Inlet OutIet
Inlet Outlet Inlet Outlet Inlet Outlet
Option code Option code RTJ-Class Option code RTJ-Class Option code

1.0619, 1.4408 all all L52 L53 CL150 H62 CL150 H63
* *
1) LESER manufactures the groove at flanged valves by milling. If a customer demands a turned surface in the soil of the groove according to DIN EN 1092-1
an additional option code is necessary: “S01: soil of the groove drilled”.
2) Smooth finish is not defined in the effective standards.

For signs and symbols refer to page 00/07

Note: Flange drillings and facings meet always the requirements of mentioned flange standards.
Flange thickness and outer diameter may vary from flange standard.

02/14 LWN 482.01-E

Type 441, 442 ANSI
Order information – Spare parts

Spare parts
Valve size 1" x 2" 11/2" x 2" 11/2" x 21/2" 2" x 3" 3" x 4" 4" x 6"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 92
Actual Orifice area A0 [mm2] 416 661 1075 1662 2827 6648
Disc (Item 7): Metal to metal seat Material-No. / Art.-No.
Disc 1.4122 210.9739.9000 210.9839.9000 210.9939.9000 210.8739.9000 220.1639.9000 220.1839.9000
detachable lifting aid 1.4404 210.9749.9000 210.9849.9000 210.9949.9000 210.8749.9000 220.1649.9000 220.1849.9000

Type 441, 442 ANSI

Disc (Item 7): Soft seal Material-No. / Art.-No.
Disc CR “K” 200.5049.9051 200.5149.9051 200.5249.9051 200.5349.9051 200.5449.9051 on request
EPDM “D” 200.5049.9041 200.5149.9041 200.5249.9041 200.5349.9041 200.5449.9041 200.5649.9041
FKM “L” 200.5049.9071 200.5149.9071 200.5249.9071 200.5349.9071 200.5449.9071 200.5649.9071
FFKM “C” 200.5049.9091 200.5149.9091 200.5249.9091 200.5349.9091 on request on request
O-ring (Item 7.4): Soft seal Material-No. / Art.-No.
O-ring CR “K” 502.0249.3551 502.0313.3551 502.0408.3551 502.0503.3551 502.0660.5351 on request
EPDM “D” 502.0249.3541 502.0313.3541 502.0408.3541 502.0503.3541 502.0660.5341 502.1041.5341
FKM “L” 502.0249.3571 502.0313.3571 502.0408.3571 502.0503.3571 502.0660.5371 502.1041.5371
FFKM “C” 502.0249.3591 502.0313.3591 502.0408.3591 502.0503.3591 on request on request
Bellows (Item 15): 1.4571 Material-No. / Art.-No.
Standard bellows 400.0949.0000 400.1049.0000 400.1149.0000 400.1249.0000 400.1349.0000 400.0849.0000
Conversion kit standard1) 5021.1041 5021.1042 5021.1043 5021.1044 5021.1045 5021.1047
Low pressure bellows 400.0949.0021 400.1049.0021 400.1149.0021 400.1249.0021 400.1349.0021 400.0849.0021
Conversion kit low pressure1) please specify in writing
Gasket – Body / bonnet (Item 60) Material-No. / Art.-No.
Gasket Graphite + 1.4401 500.0607.0000 500.0807.0000 500.1007.0000 500.1207.0000 500.1607.0000 500.2107.0000
Option code L68 Gylon (filled PTFE) 500.0605.0000 500.0805.0000 500.1005.0000 500.1205.0000 500.1605.0000 500.2105.0000
Ball (Item 61) Material-No. / Art.-No.
Ball Ball Ø [mm] 6 6 9 9 12 15
1.4404 510.0104.0000 510.0104.0000 510.0204.0000 510.0204.0000 510.0304.0000 510.0404.0000
Split ring (Item 14) Material-No. / Art.-No.
Split ring Spindle Ø [mm] 12 16 16 16 20 24
1.4404 251.0149.0000 251.0249.0000 251.0249.0000 251.0249.0000 251.0349.0000 251.0449.0000
Pin (Item 57) Material-No. / Art.-No.
Pin 1.4310 480.0505.0000 480.0705.0000 480.0705.0000 480.0705.0000 480.1005.0000 480.1105.0000

1) For pressure range see page 02/12 – 02/13.

A conversion kit contains the following components:

Item Component No.

8 Guide 1
11 Bonnet spacer 1
12 Spindle 1
15 Bellows 1
55 Stud 4, 8 depends on valve size
60 Gasket 2, 3 depends on valve size
Installation instruction LWN 037.05 1

Refer to page 02/04

LWN 482.01-E 02/15

 Type 441, 442 ANSI
Available Options For further information refer to
“Accessories and Options”, page 99/01

Heating jacket Drain hole Open bonnet

H29, H30: Couplings G 3/8, G 3/4 J18: G 1/4 See Art.-No.
H31, H32: Flanges DN 15, DN 25 J19: G 1/2
Type 441, 442 ANSI

O-ring-disc Disc with inserted sealing plate Stainless steel bellows Conversion kit for
J20: FFKM “C” J44: PTFE-FDA J68: Open bonnet stainless steel bellows
J21: CR “K” J48: PCTFE J78: Closed bonnet See Art.-No. page 02/15
J22: EPDM “D” J49: SP
J23: FKM “L”

Screwed cap H2 Plain lever H3 Packed lever H4

H2 H3 H4

Test gag Lift indicator O-ring-damper H2 O-ring-damper H4

J69: H4 J39: Adaptor H4 J65 J66
J70: H2 J93: Lift indicator

02/16 LWN 482.01-E

Type 441, 442 ANSI
Approvals

Approvals
Valve size 1" x 2" up to 4" x 6"
Actual Orifice diameter d0 [mm] 23 – 92
Actual Orifice area A0 [mm2] 416 – 6648
Europe Coefficient of discharge Kdr
PED/DIN EN ISO 4126-1 Approval No. 072020111Z0008/0/08 Rev.3
S/G 0.7

Type 441, 442 ANSI

L 0.45
Germany Coefficient of discharge α w
PED/AD 2000-Merkblatt A2 Approval No. TÜV SV 576
S/G 0.7
L 0.45
United States Coefficient of discharge K
ASME Sec. VIII Div. 1 Approval No. M37044
S/G 0.699
Approval No. M37055
L 0.521
Canada Coefficient of discharge K
Canada: CRN Approval No. For current approval no. see www.leser.com
S/G 0.699
L 0.521
China Coefficient of discharge α w
AQSIQ Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Russia Coefficient of discharge α w
GOST R / RTN Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Kazakhstan Coefficient of discharge α w
GOST-K Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Belarus Coefficient of discharge α w
GOSPROMNAZADOR Approval No. For current approval no. see www.leser.com
S/G 0.7
L 0.45
Classification societies Homepage
Bureau Veritas BV www.bureauveritas.com
The valid certification number is changed
Det Norske Veritas DNV www.dnv.com with every renewal.
Germanischer Lloyd GL www.gl-group.com
Lloyd‘ s Register EMEA LREMEA www.lr.org For a sample certificate including the valid
certification number see www.leser.com
Registro Italiano Navale RINA www.rina.org

LWN 482.01-E 02/17

 Type 441, 442 ANSI
Capacities – Steam

Capacities for saturated steam according to AD 2000-Merkblatt A2, Capacities for saturated steam according to ASME Section VIII (UV),
based on set pressure plus 10 % overpressure. Capacities at 1 bar based on set pressure plus 10% overpressure. Capacities at 2.07 bar
(14.5 psig) and below are based on 0,1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [kg/h] US Units ASME Section VIII [lb/h]

Valve size 1"x 2" 11/2" x 2" 11/2"x 21/2" 2"x 3" 3"x 4" 4"x 6" Valve size 1"x 2" 11/2"x 2" 11/2"x 21/2" 2"x 3" 3"x 4" 4"x 6"
Act. Orifice dia. d0 [mm] 23 29 37 46 60 92 Act. Orifice dia. d0 [inch] 0.91 1.14 1.46 1.81 2.36 3.62
Act. Orifice area A0 [mm2] 416 661 1075 1662 2827 6648 Act. Orifice area A0 [inch2] 0.644 1.024 1.667 2.576 4.383 10.304
LEOS/G*) [inch2] 0.462 0.734 1.195 1.847 3.142 7.387 LEOS/G*) [inch2] 0.462 0.734 1.195 1.847 3.142 7.387
Set pressure [bar] Capacities [kg/h] Set pressure [psig] Capacities [lb/h]
0.1 0 0 0 0 0 0 15 757 1204 1959 3028 5152 12113
Type 441, 442 ANSI

0.2 140 223 363 561 954 2243 20 873 1388 2259 3492 5941 13968
0.5 224 356 579 895 1523 3580 30 1105 1756 2859 4419 7519 17677
1 326 518 843 1302 2215 5209 40 1360 2162 3519 5439 9254 21757
2 519 825 1343 2075 3531 8302 50 1615 2567 4179 6459 10989 25837
3 699 1111 1808 2794 4754 11178 60 1870 2973 4839 7479 12725 29917
4 871 1385 2254 3485 5928 13938 70 2125 3378 5499 8499 14460 33997
5 1043 1658 2699 4172 7097 16687 80 2380 3783 6159 9519 16196 38078
6 1214 1930 3142 4856 8262 19426 90 2635 4189 6819 10539 17931 42158
7 1381 2196 3574 5525 9399 22098 100 2890 4594 7479 11559 19666 46238
8 1551 2466 4014 6205 10556 24818 120 3400 5405 8799 13600 23137 54398
9 1721 2736 4454 6884 11712 27535 140 3910 6216 10118 15640 26608 62558
10 1891 3006 4893 7562 12866 30250 160 4420 7027 11438 17680 30079 70719
12 2230 3545 5770 8919 15174 35675 180 4930 7838 12758 19720 33550 78879
14 2562 4073 6629 10247 17433 40987 200 5440 8648 14078 21760 37020 87039
16 2900 4610 7505 11600 19735 46400 220 5950 9459 15398 23800 40491 95200
18 3239 5149 8382 12955 22041 51820 240 6460 10270 16718 25840 43962 103360
20 3578 5688 9260 14312 24350 57249 260 6970 11081 18038 27880 47433 111520
22 3907 6212 10111 15629 26590 62515 280 7480 11892 19358 29920 50904 119680
24 4247 6752 10991 16988 28903 67953 300 7990 12703 20677 31960 54375 127841
26 4588 7294 11873 18351 31222 73405 320 8500 13513 21997 34000 57845 136001
28 4930 7837 12757 19718 33547 78873 340 9010 14324 23317 36040 61316 144161
30 5272 8382 13644 21089 35880 84358 360 9520 15135 24637 38080 64787 152321
32 5616 8929 14534 22465 38220 89860 380 10030 15946 25957 40120 68258 160482
34 5945 9451 15384 23779 40455 95115 400 10540 16757 27277 42161 71729 168642
36 6290 10000 16278 25160 42806 420 11050 17567 28597 44201 75199 176802
38 6637 10551 17175 26547 45165 440 11560 18378 29917 46241 78670 184963
40 6985 11104 18076 27939 47533 460 12070 19189 31236 48281 82141 193123
42 7334 11660 18980 29337 480 12580 20000 32556 50321 85612 201283
44 7685 12218 19888 30740 500 13090 20811 33876 52361 89083 209443
46 8037 12778 20800 32150 550 14365 22838 37176 57461 97760
48 8391 13341 33566 600 15640 24865 40476 62561
50 8747 34988 650 16915 26892 43775 67661
51 8900 35600 700 18190 28919 72762
740 19210 76842

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

02/18 LWN 482.01-E

Type 441, 442 ANSI
Capacities – Air

Capacities for air according to AD 2000-Merkblatt A2, based on set pres- Capacities for air according to ASME Section VIII (UV), based on set
sure plus 10 % overpressure at 0 °C and 1013 mbar. Capacities at 1 bar pressure plus 10 % overpressure at 16 °C (60 °F). Capacities at 2.07
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. bar (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [mn3/h] US Units ASME Section VIII [S.C.F.M.]

Valve size 1"x 2" 11/2" x 2" 11/2"x 21/2" 2"x 3" 3"x 4" 4"x 6" Valve size 1"x 2" 11/2"x 2" 11/2"x 21/2" 2"x 3" 3"x 4" 4"x 6"
Act. Orifice dia. d0 [mm] 23 29 37 46 60 92 Act. Orifice dia. d0 [inch] 0.91 1.14 1.46 1.81 2.36 3.62
Act. Orifice area A0 [mm2] 416 661 1075 1662 2827 6648 Act. Orifice area A0 [inch2] 0.644 1.024 1.667 2.576 4.383 10.304
LEOS/G*) [inch2] 0.462 0.734 1.195 1.847 3.142 7.387 LEOS/G*) [inch2] 0.462 0.734 1.195 1.847 3.142 7.387
Set pressure [bar] Capacities [mn3/h] Set pressure [psig] Capacities [S.C.F.M.]
0.1 0 0 0 0 0 0 15 270 429 698 1079 1835 4315

Type 441, 442 ANSI

0.2 162 258 420 649 1105 2597 20 311 494 805 1244 2116 4976
0.5 263 418 680 1051 1789 4206 30 394 626 1019 1574 2679 6297
1 388 617 1004 1552 2641 6209 40 484 770 1254 1938 3297 7750
2 627 996 1622 2507 4265 10026 50 575 915 1489 2301 3915 9204
3 854 1357 2209 3414 5809 13657 60 666 1059 1724 2664 4533 10657
4 1071 1703 2773 4286 7291 17143 70 757 1204 1959 3028 5152 12111
5 1289 2050 3337 5157 8774 20629 80 848 1348 2194 3391 5770 13564
6 1507 2396 3900 6029 10257 24114 90 939 1492 2430 3754 6388 15018
7 1725 2742 4464 6900 11739 27600 100 1029 1637 2665 4118 7006 16471
8 1943 3089 5028 7771 13222 31086 120 1211 1926 3135 4845 8243 19378
9 2161 3435 5592 8643 14704 34571 140 1393 2215 3605 5571 9479 22285
10 2379 3781 6155 9514 16187 38057 160 1574 2504 4076 6298 10716 25192
12 2814 4474 7283 11257 19152 45028 180 1756 2792 4546 7025 11952 28099
14 3250 5167 8411 13000 22117 52000 200 1938 3081 5016 7751 13189 31006
16 3686 5859 9538 14743 25082 58971 220 2120 3370 5486 8478 14425 33913
18 4121 6552 10666 16486 28047 65942 240 2301 3659 5957 9205 15662 36820
20 4557 7245 11793 18228 31012 72913 260 2483 3948 6427 9932 16898 39727
22 4993 7938 12921 19971 33977 79885 280 2665 4237 6897 10658 18135 42633
24 5429 8630 14048 21714 36943 86856 300 2846 4526 7368 11385 19371 45540
26 5864 9323 15176 23457 39908 93827 320 3028 4815 7838 12112 20608 48447
28 6300 10016 16304 25200 42873 100799 340 3210 5104 8308 12839 21844 51354
30 6736 10708 17431 26942 45838 107770 360 3391 5392 8778 13565 23081 54261
32 7171 11401 18559 28685 48803 114741 380 3573 5681 9249 14292 24317 57168
34 7607 12094 19686 30428 51768 121713 400 3755 5970 9719 15019 25554 60075
36 8043 12786 20814 32171 54733 420 3936 6259 10189 15745 26791 62982
38 8478 13479 21941 33914 57698 440 4118 6548 10660 16472 28027 65889
40 8914 14172 23069 35657 60663 460 4300 6837 11130 17199 29264 68796
42 9350 14864 24197 37399 480 4481 7126 11600 17926 30500 71703
44 9786 15557 25324 39142 500 4663 7415 12070 18652 31737 74610
46 10221 16250 26452 40885 550 5117 8137 13246 20469 34828
48 10657 16942 42628 600 5572 8859 14422 22286
50 11093 44371 650 6026 9581 15598 24103
51 11311 45242 700 6480 10303 25920
740 6843 27373

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

LWN 482.01-E 02/19

 Type 441, 442 ANSI
Capacities – Water

Capacities for water according to AD 2000-Merkblatt A2. based on set Capacities for water according to ASME Section VIII (UV). based on set
pressure plus 10 % overpressure at 20 °C (68 °F). Capacities at 1 bar pressure plus 10 % overpressure at 21 °C (70 °F). Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [103kg/h] US Units ASME Section VIII [US-G.P.M.]

Valve size 1"x 2" 11/2" x 2" 11/2"x 21/2" 2"x 3" 3"x 4" 4"x 6" Valve size 1"x 2" 11/2"x 2" 11/2"x 21/2" 2"x 3" 3"x 4" 4"x 6"
Act. Orifice dia. d0 [mm] 23 29 37 46 60 92 Act. Orifice dia. d0 [inch] 0.91 1.14 1.46 1.81 2.36 3.62
Act. Orifice area A0 [mm2] 416 661 1075 1662 2827 6648 Act. Orifice area A0 [inch2] 0.644 1.024 1.667 2.576 4.383 10.304
LEOL*) [inch2] 0.516 0.821 1.336 2.065 3.513 8.259 LEOL*) [inch2] 0.516 0.821 1.336 2.065 3.513 8.259
Set pressure [bar] Capacities [103kg/h] Set pressure [psig] Capacities [US-G.P.M.]
0.1 4.25 6.76 11.0 17.0 28.9 68.0 15 54.0 85.9 140 216 368 864
Type 441, 442 ANSI

0.2 5.21 8.28 13.5 20.8 35.4 83.3 20 61.1 97.1 158 244 416 977
0.5 7.37 11.7 19.1 29.5 50.1 118 30 73.1 116 189 293 498 1170
1 10.0 15.9 25.8 39.9 67.9 160 40 84.5 134 219 338 575 1351
2 14.1 22.4 36.5 56.4 96.0 226 50 94.4 150 244 378 643 1511
3 17.3 27.5 44.7 69.1 118 276 60 103 164 268 414 704 1655
4 19.9 31.7 51.6 79.8 136 319 70 112 178 289 447 760 1787
5 22.3 35.5 57.7 89.2 152 357 80 119 190 309 478 813 1911
6 24.4 38.8 63.2 97.7 166 391 90 127 201 328 507 862 2027
7 26.4 42.0 68.3 106 180 422 100 134 212 346 534 909 2136
8 28.2 44.8 73.0 113 192 451 120 146 233 379 585 996 2340
9 29.9 47.6 77.4 120 204 479 140 158 251 409 632 1075 2528
10 31.5 50.1 81.6 126 215 505 160 169 269 437 676 1150 2702
12 34.6 54.9 89.4 138 235 553 180 179 285 464 717 1219 2866
14 37.3 59.3 96.6 149 254 597 200 189 300 489 755 1285 3021
16 39.9 63.4 103 160 271 638 220 198 315 513 792 1348 3169
18 42.3 67.3 110 169 288 677 240 207 329 535 827 1408 3310
20 44.6 70.9 115 178 304 714 260 215 342 557 861 1465 3445
22 46.8 74.4 121 187 318 748 280 223 355 578 894 1521 3575
24 48.9 77.7 126 195 333 782 300 231 368 599 925 1574 3700
26 50.9 80.9 132 203 346 814 320 239 380 618 955 1626 3822
28 52.8 83.9 137 211 359 844 340 246 391 637 985 1676 3939
30 54.6 86.8 141 219 372 874 360 253 403 656 1013 1724 4054
32 56.4 89.7 146 226 384 903 380 260 414 674 1041 1772 4165
34 58.2 92.5 151 233 396 931 400 267 425 691 1068 1818 4273
36 59.8 95.1 155 239 407 420 274 435 708 1095 1862 4378
38 61.5 97.7 159 246 418 440 280 445 725 1120 1906 4481
40 63.1 100 163 252 429 460 286 455 741 1146 1949 4582
42 64.6 103 167 259 480 293 465 757 1170 1991 4681
44 66.2 105 171 265 500 299 475 773 1194 2032 4777
46 67.6 108 175 271 550 313 498 811 1253 2131
48 69.1 110 276 600 327 520 847 1308
50 70.5 282 650 340 541 881 1362
51 71.2 285 700 353 562 1413
740 363 1453

*) LEOL = LESER Effective Orifice liquids please refer to page 00/12

How to use capacity-sheets please refer to page 00/09

02/20 LWN 482.01-E

Type 441, 442 ANSI
h = Lift [mm]
Determination of coefficent of discharge d0 = Flow diameter [mm] of selected safety
in case of lift restriction or back pressure valve, refer to table article numbers
h/d0 = Ratio of lift / flow diameter
pa0 = Back pressure [bara]
p0 = Set pressure [bara]
pa0 / p0 = Ratio of back pressure / set pressure
Kdr = Coefficient of discharge
acc. to DIN EN ISO 4126-1
αw = Coefficient of discharge
Diagram for evaluation of ratio of lift / flow diameter (h/d0) acc. to AD 2000-Merkblatt A2
in reference to the coefficient of discharge (Kdr / αw) Kb = Back pressure correction factor
acc. to API 520 topic 3.3

Kdr = αw = f (h/d0) How to use please refer to page 00/08

0.800

1" – 4" S/G

0.700

0.600

Type 441, 442 ANSI

0.500

0.400
Coefficient of discharge Kdr / αw

1" – 4" L
0.300

0.200

0.100

0
0 0.050 0.100 0.150 0.200 0.250 0.300
0.243
Ratio of lift / flow diameter h / d0

Diagram for evaluation of coefficient of discharge (Kdr / αw) or Kb

in reference to the ratio of back pressure / set pressure (pa0 / p0)

Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0)

0.8

0.7 1.0

0.9
0.6
0.8
0.5 0.7

0.6
Back pressure correction factor Kb

0.4
Coefficient of discharge Kdr / αw

0.5
0.3
0.4

0.2 0.3

0.2
0.1
0.1

0 0
0.2 0.3 0.4 0.5 0.6 0.7 0.8
0.91
Ratio of back pressure / set pressure pa0 / p0

LWN 482.01-E 02/21

 Type 441, 442 ANSI
Type 441, 442 ANSI

02/22 LWN 482.01-E

 Type
441 XXL
442 XXL
Flanged Safety Relief Valves
– spring loaded

Type 441, 442 XXL

Contents Chapter/Page

Materials
• Conventional design 03/02
• Balanced bellows design 03/04
How to order
• Numbering system 03/06
• Article numbers 03/08
Dimensions and weights
• Metric Units 03/10
• US Units 03/11
Pressure temperature ratings
• Metric Units 03/12
• US Units 03/13
Flange drillings and facings 03/14
Order information – Spare parts 03/15
Available options 03/16
Approvals 03/17
Capacities
• Steam [Metric Units + US Units] 03/18
• Air [Metric Units + US Units] 03/19
• Water [Metric Units + US Units] 03/20
Determination of coefficient 03/21
Type 441 XXL
Packed lever
of discharge Kdr /α w
Closed bonnet
Conventional and
balanced bellows design

LWN 482.01-E 03/01

 Type 441, 442 XXL
Conventional design

40 Bolted Cap H1

18 Adjusting screw

19 Lock nut
69 Needle bearing

16 Upper spring plate

9 Bonnet

12 Spindle
54 Spring
Type 441, 442 XXL

14 Split ring

17 Lower spring plate

55 Stud

56 Nut

60 Gasket

8 Guide with bushing

22 Lift stopper

21 Lift stopper
57 Pin
61 Ball
7 Disc
5 Seat

1 Body
88 Spacer
87 Plug

03/02 LWN 482.01-E

Type 441, 442 XXL
Conventional design

Materials
Item Component Type 4412 XXL / 4422 XXL Type 4414 XXL

1.4060/1.0425 1.4571
1 Body
Carbon steel 316Ti
1.0305 stellited, 1.0460 stellited 1.4571
5 Seat
Carbon steel, stellited 316Ti
1.4404 1.4571
7 Disc
316L 316Ti
DN 200 – 250: 0.7040 1.4404
Guide with bushing Ductile Gr. 60-40-18 / Chrome steel 316L
8
DN 300 – 400: 1.4404 1.4404
Guide 316L 316L
0.7043 or 1.0254 1.4571
9 Bonnet
Ductile Gr. 60-40-18 or Steel 316Ti
1.4021 1.4404
12 Spindle
420 316L

Type 441, 442 XXL

1.4104 1.4404
14 Split ring
Chrome steel 316L
1.0570 or 1.4404 1.4404
16 / 17 Spring plate
Steel or 316L 316L
Adjusting screw 1.4104 PTFE 1.4404 PTFE
18
with bushing Chrome steel PTFE 316L PTFE
1.4404 1.4404
19 Lock nut
316L 316L
1.4404 1.4404
21 / 22 Lift stopper
316L 316L
0.7040 1.4404
40 Bolted cap H1
Ductile Gr. 60-40-18 316L
1.1200, 1.8159, 1.7102 1.4310
Spring standard
Carbon steel Stainless steel
54
1.4310 –
Spring optional
Stainless steel –
1.4401 1.4401
55 Stud
B8M B8M
1.4401 1.4401
56 Nut
8M 8M
1.4310 1.4310
57 Pin
Stainless steel Stainless steel
Graphite / 1.4401 Graphite / 1.4401
60 Gasket
Graphite / 316 Graphite / 316
1.3541 1.4401
61 Ball
Hardened stainless steel 316
1.4401 1.4401
69 Needle bearing
316L 316L
1.4401 / 1.4571 1.4401 / 1.4571
87 / 88 Plug / Spacer
316 / 316Ti 316 / 316Ti

Please notice:

- Modifications reserved by LESER

- If several materials are specified LESER defines the material.
- LESER can upgrade materials without notice.
- Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 03/03

 Type 441, 442 XXL
Balanced bellows design

40 Bolted Cap H1

18 Adjusting screw

19 Lock nut

69 Needle bearing

16 Upper spring plate

9 Bonnet

12 Spindle
Type 441, 442 XXL

54 Spring

14 Split ring

17 Lower spring plate

55 Stud

56 Nut

60 Gasket
8 Guide with bushing
15 Bellows
22 Lift stopper
57 Pin
61 Ball
7 Disc
5 Seat
1 Body
88 Spacer
87 Plug

03/04 LWN 482.01-E

Type 441, 442 XXL
Balanced bellows design

Materials
Item Component Type 4412 XXL / 4422 XXL Type 4414 XXL

1.4060/1.0425 1.4571
1 Body
Carbon steel 316Ti
Seat 1.0305 stellited 1.4571
DN 200 – 250 Carbon steel, stellited 316Ti
5
1.0460 stellited 1.4571
DN 300 – 400
Carbon steel, stellited 316Ti
1.4404 1.4571
7 Disc
316L 316Ti
1.4571 1.4571
8 Guide
316Ti 316Ti
0.7043 or 1.0254 1.4571
9 Bonnet
Ductile Gr. 60-40-18 or Steel 316Ti
1.4404 1.4404
12 Spindle
316L 316L

Type 441, 442 XXL

1.4104 1.4404
14 Split ring
Chrome steel 316L
1.4571 1.4571
15 Bellows
316Ti 316Ti
1.0570 or 1.4404 1.4404
16 / 17 Spring plate
Steel or 316L 316L
Adjusting screw 1.4104 PTFE 1.4404 PTFE
18
with bushing Chrome steel PTFE 316L PTFE
1.4404 1.4404
19 Lock nut
316L 316L
1.4404 1.4404
22 Lift stopper
316L 316L
0.7040 1.4404
40 Bolted cap H1
Ductile Gr. 60-40-18 316L
1.1200, 1.8159, 1.7102 1.4310
Spring standard
Carbon steel Stainless steel
54
1.4310 –
Spring optional
Stainless steel –
1.4401 1.4401
55 Stud
B8M B8M
1.4401 1.4401
56 Nut
8M 8M
1.4310 1.4310
57 Pin
Stainless steel Stainless steel
Graphite / 1.4401 Graphite / 1.4401
60 Gasket
Graphite / 316 Graphite / 316
1.3541 1.4401
61 Ball
Hardened stainless steel 316
1.4401 1.4401
69 Needle bearing
316L 316L
1.4401 / 1.4571 1.4401 / 1.4571
87 / 88 Plug / Spacer
316 / 316Ti 316 / 316Ti

Please notice:

- Modifications reserved by LESER

- If several materials are specified LESER defines the material.
- LESER can upgrade materials without notice.
- Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 03/05

 Type 441, 442 XXL
How to order – Example for Numbering system

1 Article Number
2 Set Pressure
3 Connections

4412.4752 5 barg H45

Please state unit (in gauge)! Please refer to page 03/14

1 2 3 4
Please do not exceed the pressure
441 2 . 475 2 range defined in the spring charts.

1 Valve Type 441, 442 XXL

Type 441, 442 XXL

Type 441 – with closed bonnet

Type 442 – with open bonnet

2 Material code

Code Body material

1.0460/1.0425
2
(Carbon steel)

4 1.4571 (316Ti)

3 Valve code
Identifies valve size and body
material, refer to page 03/09.

Code Lifting lever

2 bolted cap H1

bolted
4 lifting device H6

bolted
5 H3
lifting device

03/06 LWN 482.01-E

Type 441, 442 XXL

4 Options
5 Documentation
6
Code and Medium

J22 H01 L30 2.0

Type 441, 442 XXL Option code Please select requested documentation:
1 2
• O-ring-disc
Inspections, tests: Option code 2 . 0
CR “K” J21
DIN EN 10204-3.2: TÜV-Nord
EPDM “D” J22
Certificate for test pressure M33 1 Code
FKM “L” J23

Type 441, 442 XXL

FFKM “C” J20 1. ASME Section VIII
LESER CGA (Certificate H03 2. CE / VdTUEV
• Disc 1.4404 / 316L stellited J25 for Global Application 3. ASME Section VIII
• Seat stellited L61 - Inspection certificate 3.1 acc. + CE / VdTUEV
to DIN EN 10204
• Stainless steel bel lows
- open bonnet (Type 442) J68 - Declaration of conformity acc.
- closed bonnet (Type 441) J78 to PED 97/23/EC Medium
2
• High temperature alloy spring X01 .1 Gases
Material test certificate: .2 Liquids
• Stainless steel spring X04
DIN EN 10204-3.1 .3 Steam
• Adaptor for lift indicator H6 J39
• Lift indicator J93 .0 Steam / Gases / Liquids
Part Option code (valid only for CE / VdTUEV)
• Test gag Body H01
- bolted cap H1 J70
Bonnet L30
- bolted lifting device H6 J69
Cap / lever cover L31
• Seat 1.4404 / 316L stellited L61
Disc L23
• Drain hole G 1/2 J19 Studs N07
• Free of oil and grease J85 Nuts N08
• Materials
- NACE N78

Option code applies only

if not standard

LWN 482.01-E 03/07

 Type 441, 442 XXL
How to order – Article numbers
Type 441, 442 XXL

Type 441 XXL

Bolted cap H1
Closed bonnet
Conventional and
balanced bellows design

Type 441 XXL

Bolted lifting device H6
Closed bonnet
Conventional and
balanced bellows design

Type 442 XXL

Bolted lifting device H6
Open bonnet
Conventional and
balanced bellows design

03/08 LWN 482.01-E

Type 441, 442 XXL
How to order – Article numbers

Article numbers
DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x16" 16" x 20"
Actual Orifice diameter d0 [mm] 165 200 235 295
Actual Orifice area A0 [mm2] 21382 31416 43374 68349
Body material: 1.0460 / 1.0425 (Carbon steel)
Bonnet H1 Art.-No. 4412. 4752 4762 4772 4782
closed H3 Art.-No. 4412. – – – –
H6 Art.-No. 4412. 4754 4764 4774 4784
open H6 Art.-No. 4422. 4755 4765 4775 4785
Body material: 1.4571 (316Ti)
Bonnet H1 Art.-No. 4414. 4792 4802 4902 4912
closed H6 Art.-No. 4414. 4794 4804 4904 4914

Type 441, 442 XXL

LWN 482.01-E 03/09

 Type 441, 442 XXL
Dimensions and weights

Metric Units
DNI+o 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x14" 12" x 16" 16" x 20"
Actual Orifice diameter d0 [mm] 165 200 235 295
Actual Orifice area A0 [mm2] 21382 31416 43374 68349

Weight 285 335 384 588

[kg] with bellows 289 340 390 595
Center to face Inlet a 305 340 330 400
[mm] Outlet b 300 325 3941) 4771)
Height (H4) Standard H max. 1473 1518 1633 1953
[mm] Bellows H max. 1473 1518 1633 1953
Support brackets A 470 514 640 800
[mm] B 150 150 180 220
(drilled only on request) C Ø 18 Ø 18 Ø 24 Ø 28
D 305 340 330 400
Type 441, 442 XXL

E 20 20 20 20

Body material: 1.0460 / 1.0425 (Carbon steel)

DIN Flange2) Inlet PN 25 PN 16
Outlet PN 10
Body material: 1.4571 (316Ti)
DIN Flange2) Inlet PN 25 PN 16
Outlet PN 10

1) For pressure rating outlet higher than PN 10 centre to face dimension will change
2) Standard flange rating. For other flange drillings and facings please refer to page 03/14.

E
C

B
D

Conventional and balanced bellows design Support brackets

03/10 LWN 482.01-E

Type 441, 442 XXL
Dimensions and weights

US Units
DNI+o 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x14" 12" x 16" 16" x 20"
Actual Orifice diameter d0 [inch] 6.5 7.87 9.25 11.61
Actual Orifice area A0 [inch2] 33.143 48.695 67.229 105.942

Weight 628 739 847 1297

[Ibs] with bellows 637 750 860 1312
3/ 13 15 3/4
Center to face Inlet a 12 13 8
(CL300: 13 3/4) (CL300: 16 5/32)
[inch] Outlet b 11 13/16 12 13/16 15 1/2 18 25/32
Height (H4) Standard H max. 58 59 3/ 64 5/ 76 7/8
4 16
[inch] Bellows H max. 58 59 3/ 64 5/ 76 7/8
4 16
Support brackets A 18 1/
2 20 1/
4 25 3/
16 31 1/2
[inch] B 5 29/32 5 29/32 7 3/32 8 21/32
(drilled only on request) C Ø 29/
32 Ø 23/
32 Ø 15/
16 Ø 3/32
D 12 13 3/8 13 15 3/4

Type 441, 442 XXL

E 25/ 25/ 25/ 25/
32 32 32 32

Body material: 1.0460 / 1.0425 (Carbon steel)

ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150 or CL300
Body material: 1.4571 (316Ti)
ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150 or CL300

1) Standard flange rating. For other flange drillings and facings please refer to page 03/14.

E
C

B
D

Conventional and balanced bellows design Support brackets

LWN 482.01-E 03/11

 Type 441, 442 XXL
Pressure temperature ratings

Metric Units
DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Actual Orifice diameter d0 [mm] 165 200 235 295
Actual Orifice area A0 [mm2] 21382 31416 43374 68349
Body material: 1.0460 / 1.0425 (Carbon steel)
DIN Flange Inlet PN 25 PN16
Outlet PN 10
Minimum
set pressure p [barg] S/G/L 0.2 0.2 0.2 0.2

Min. set pressure1)

standard bellows p [barg] S/G/L 0.2 0.2 0.2 0.2

Min. set pressure

low press. bellows p [barg] S/G/L – – – –

Maximum
set pressure p [barg] S/G/L 20 13.4 9.25 1.25
Type 441, 442 XXL

Max. set pressure

with special spring p [barg] S/G/L 25 16 16 8

Temperature min. [°C] -85

acc. to DIN EN max. [°C] +420
Temperature min. [°C] -29
acc. to ASME max. [°C] +427

Body material: 1.4571 (316Ti)

DIN Flange Inlet PN 25 PN 16
Outlet PN 10
Minimum
set pressure p [barg] S/G/L 0.2 0.2 0.2 0.2

Min. set pressure1)

standard bellows p [barg] S/G/L 0.2 0.2 0.2 0.2

Min. set pressure

low press. bellows p [barg] S/G/L – – – –

Maximum
set pressure p [barg] S/G/L 1.45 0 0 0

Max. set pressure

with special spring p [barg] S/G/L 10 6 3.57 2.3

Temperature min. [°C] -196

acc. to DIN EN max. [°C] +550
Temperature min. [°C] -184
acc. to ASME max. [°C] +427

1)
Min. set pressure standard bellows = Max. set pressure low pressure bellows.

03/12 LWN 482.01-E

Type 441, 442 XXL
Pressure temperature ratings

US Units
DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Actual Orifice diameter d0 [inch] 6.5 7.87 9.25 11.61
Actual Orifice area A0 [inch2] 33.143 48.695 67.229 105.942
Body material: 1.0460 / 1.0425 (Carbon steel)
ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150
Minimum
set pressure p [psig] S/G/L 2.9 2.9 2.9 2.9

Min. set pressure2)

standard bellows p [psig] S/G/L 2.9 2.9 2.9 2.9

Min. set pressure

low press. bellows p [psig] S/G/L – – – –

Maximum
set pressure p [psig] S/G/L 290 194 134 18

Type 441, 442 XXL

Max. set pressure
with special spring p [psig] S/G/L 363 232 232 116

Temperature min. [°F] -121

acc. to DIN EN max. [°F] +788
Temperature min. [°F] -300
acc. to ASME max. [°F] +800

Body material: 1.4571 (316Ti)

ANSI Flange Inlet CL150 or CL300
Class1) Outlet CL150
Minimum
set pressure p [psig] S/G/L 2.9 2.9 2.9 2.9

Min. set pressure2)

standard bellows p [psig] S/G/L 2.9 2.9 2.9 2.9

Min. set pressure

low press. bellows p [psig] S/G/L – – – –

Maximum
set pressure p [psig] S/G/L 21 0 0 0

Max. set pressure

with special spring p [psig] S/G/L 145 87 52 33

Temperature min. [°F] -321

acc. to DIN EN max. [°F] +1022
Temperature min. [°F] -300
acc. to ASME max. [°F] +800

1) For flange rating class 150 the pressure temperature ratings according to ASME ANSI B 16.34 apply.
2)
Min. set pressure standard bellows = Max. set pressure low pressure bellows.

LWN 482.01-E 03/13

 Type 441, 442 XXL
Flange drillings and facings

Flange drillings
DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Actual Orifice diameter d0 [mm] 165 200 235 295
Actual Orifice area A0 [mm2] 21382 31416 43374 68349
Body material: 1.0460 / 1.0425 (Carbon steel), 1.4571 (316Ti)
PN 10 H44 H44 H44 H44
PN 16 H45 H45
DIN EN 1092
PN 25
*
H46
*
H46
Inlet
PN 40
*– *– – –
CL150 H64 H64 H64 H64
ASME B16.5
CL300 H65 – – –
PN 10
PN 16
*
H51
*
H51
*
H51
*
H51
DIN EN 1092
PN 25 – – – –
Outlet
PN 40 – – – –
CL150 H79 H79 H79 H79
ASME B16.5
CL300 – – – –
Type 441, 442 XXL

Flange facings
Indication Standard Inlet Outlet Remark
General
Flange undrilled – H38 H39
Linde-V-Nut, Form V48 Linde Standard 420-08 J07 J08 Groove: Rz 16
Linde-V-Nut, Form V48A LWN 313.36 J05 J06 Groove: Rz 4, e.g. with hydrogen
Lens seal form L DIN 2696
J11 J12
(without sealing lens) LWN 313.35
Acc. to DIN EN 1092
Inlet Outlet Remark
Flange facing Rz-data according to
PN 10 – PN 40 PN 10 – PN 40
(see also LWN 313.40) DIN EN 1092 in μm
Type B1 Facing: Rz = 12.5 – 50
Raised face * *
Type B2 L36 L38 Facing: Rz = 3.2 – 12.5
Tongue face C1) H94 H92
Steel flanges only

Groove face D1) H93 H91

Male face E H96 H98
Female face F H97 H99
O-ring male face G J01 J02
O-ring female face H J03 J04
Acc. to ASME B16.5
Smooth Serrated
RTJ-Nut
Finish Finish
Body material Inlet Outlet
Inlet Outlet Inlet Outlet Inlet Outlet
Option code Option code RTJ-Class Option code RTJ-Class Option code

1.0619, 1.4408 all all L52 L53 CL150 H62 CL150 H63
* *
1) LESER manufactures the groove at flanged valves by milling. If a customer demands a turned surface in the soil of the groove according to DIN EN 1092-1
an additional option code is necessary: “S01: soil of the groove drilled”.
2) Smooth finish is not defined in the effective standards.

For signs and symbols refer to page 00/07

Note: Flange drillings and facings meet always the requirements of mentioned flange standards.
Flange thickness and outer diameter may vary from flange standard.

03/14 LWN 482.01-E

Type 441, 442 XXL
Order information – Spare parts

Spare parts
DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Actual Orifice diameter d0 [mm] 165 200 235 295
Actual Orifice area A0 [mm2] 21382 31416 43374 68349
Disc (Item 7): Metal to metal seat Material-No. / Art.-No.
Disc
1.4571 230.1549.9000 230.1649.9000 200.2349.9000 200.2449.9000
with detachable lifting aid
Bellows (Item 15): 1.4571 Material-No. / Art.-No.
Standard bellows 1.4571 400.5449.0000 400.5349.0000 on request on request
Conversion kit standard1) single parts single parts on request on request
Gasket – Body / bonnet (Item 60) Material-No. / Art.-No.
Gasket Graphite + 1.4401 500.2807.0000 500.2807.0000 500.3507.0000 500.3607.0000
Ball (Item 61) Material-No. / Art.-No.
Ball Ball Ø [mm] 18 18 18 18
1.4401 510.0504.0000 510.0504.0000 510.0504.0000 510.0504.0000
Split ring (Item 14) Material-No. / Art.-No.
Split ring Spindle ø [mm] 35 35 35 35

Type 441, 442 XXL

1.4404 251.1549.0000 251.1549.0000 – –
Pin (Item 57) Material-No. / Art.-No.
Pin 1.4310 480.1405.0000 480.1405.0000 480.0605.0000 480.0605.0000

1) For pressure range see page 03/12 – 03/13.

A conversion kit contains the following components:

Item Component No.

8 Guide 1
11 Bonnet spacer –
12 Spindle 1
15 Bellows 1
22 Lift stopper 1
60 Gasket 3
Installation instruction LWN 037.05 1

Refer to page 03/04

LWN 482.01-E 03/15

 Type 441, 442 XXL
Available Options For further information refer to
“Accessories and Options”, page 99/01

Drain hole Open bonnet

J19: G 1/2 See Art.-No.

Disc 316L stellited Stainless steel bellows

J25 J68: Open bonnet
J78: Closed bonnet
Type 441, 442 XXL

Bolted cap H1 Bolted lifting device H6

H1 H6

Test gag Lift indicator

J69: Bolted lifting device H6 J39: Adaptor for lift indicator H6
J70: Bolted cap H1 J93: Lift indicator

03/16 LWN 482.01-E

Type 441, 442 XXL
Approvals

Approvals
DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Actual Orifice diameter d0 [mm] 1665 200 235 295
Actual Orifice area A0 [mm2] 21382 31416 43374 68349
Europe Coefficient of discharge Kdr
PED/DIN EN ISO 4126-1 Approval No. 072020111Z0008/0/08 Rev.3
S/G 0.75 0.7 0.7 0.7
L 0.56 0.52 0.52 0.52
Germany Coefficient of discharge α w
PED/AD 2000-Merkblatt A2 TÜV SV 576
S/G 0.75 0.7 0.7 0.7
L 0.56 0.52 0.52 0.52
United States Coefficient of discharge K
ASME Sec. VIII Div. 1 Approval No. M37044
S/G 0.699
Approval No.

Type 441, 442 XXL

M37055
L 0.521
Canada Coefficient of discharge K
Canada: CRN Approval No. For current approval no. see www.leser.com
S/G 0.699
L 0.521
China Coefficient of discharge α w
AQSIQ Approval No. For current approval no. see www.leser.com
S/G 0.75 0.7 0.7 0.7
L 0.56 0.52 0.52 0.52
Russia Coefficient of discharge α w
GOST R / RTN Approval No. For current approval no. see www.leser.com
S/G 0.75 0.7 0.7 0.7
L 0.56 0.52 0.52 0.52
Kazakhstan Coefficient of discharge α w
GOST-K Approval No. For current approval no. see www.leser.com
S/G 0.75 0.7 0.7 0.7
L 0.56 0.52 0.52 0.52
Belarus Coefficient of discharge α w
GOSPROMNAZADOR Approval No. For current approval no. see www.leser.com
S/G 0.75 0.7 0.7 0.7
L 0.56 0.52 0.52 0.52
Classification societies Homepage
Bureau Veritas BV www.bureauveritas.com
The valid certification number is changed
Det Norske Veritas DNV www.dnv.com with every renewal.
Germanischer Lloyd GL www.gl-group.com
Lloyd‘ s register EMEA LREMEA www.lr.org For a sample certificate including the valid
certification number see www.leser.com
Registro Italiano Navale RINA www.rina.org

LWN 482.01-E 03/17

 Type 441, 442 XXL
Capacities – Steam

Capacities for saturated steam according to AD 2000-Merkblatt A2, Capacities for saturated steam according to ASME Section VIII (UV),
based on set pressure plus 10 % overpressure. Capacities at 1 bar based on set pressure plus 10% overpressure. Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [kg/h] US Units ASME Section VIII [lb/h]

DNI+O 200 x 300 250 x 350 300 x 400 400 x 500 DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20" Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Act. Orifice dia. d0 [mm] 165 200 235 295 Act. Orifice dia. d0 [inch] 6.5 7.87 9.25 11.61
Act. Orifice area A0 [mm2] 21382 31416 43374 68349 Act. Orifice area A0 [inch2] 33.14 48.69 67.23 105.94
LEOS/G*) [inch2] 23.761 34.910 48.198 75.952 LEOS/G*) [inch2] 23.761 34.910 48.198 75.952
Set pressure [bar] Capacities [kg/h] Set pressure [psig] Capacities [lb/h]
0.1 0 0 0 0 15 38962 57245 79034 124543
0.2 7214 0 14633 0 20 44928 66009 91134 143612
0.5 11516 16920 23360 36811 30 56859 83539 115336 181749
1 16755 24617 33986 53556 40 69983 102821 141958 223700
2 26704 39234 54168 85359 50 83107 122104 168579 265652
3 35954 52826 72932 114929 60 96231 141386 195201 307603
4 48036 65872 90944 143312 70 109355 160668 221823 349554
5 57507 78859 108875 171568 80 122479 179951 248444 391505
6 66947 91804 126747 199731 90 135603 199233 275066
Type 441, 442 XXL

7 76157 104433 144183 100 148727 218515 301688

8 85532 117289 161932 120 174975 257080 354931
9 94895 130128 179658 140 201223 295645 408174
10 104250 142957 197370 160 227471 334209 461418
12 122947 168596 232768 180 253719 372774
14 141254 193700 200 279967 411338
16 159910 219283 220 306215 449903
18 178589 244897 240 332463 488468
20 197298 260 358711 527032
22 197298 280 384960
24 234188 300 411208
320 437456
340 463704
360 489952

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

03/18 LWN 482.01-E

Type 441, 442 XXL
Capacities – Air

Capacities for air according to AD 2000-Merkblatt A2, based on set pres- Capacities for air according to ASME Section VIII (UV), based on set
sure plus 10 % overpressure at 0 °C and 1013 mbar. Capacities at 1 bar pressure plus 10 % overpressure at 16 °C (60 °F). Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [mn3/h] US Units ASME Section VIII [S.C.F.M.]

DNI+O 200 x 300 250 x 350 300 x 400 400 x 500 DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20" Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Act. Orifice dia. d0 [mm] 165 200 235 295 Act. Orifice dia. d0 [inch] 6.5 7.87 9.25 11.61
Act. Orifice area. A0 [mm2] 21382 31416 43374 68349 Act. Orifice area. A0 [inch2] 33.14 48.69 67.23 105.94
LEOS/G*) [inch2] 23.761 34.910 48.198 75.952 LEOS/G*) [inch2] 23.761 34.910 48.198 75.952
Set pressure [bar] Capacities [mn3/h] Set pressure [psig] Capacities [S.C.F.M.]
0.1 0 0 0 0 15 13879 20392 28153 44365
0.2 8354 0 16945 0 20 16004 23514 32464 51158
0.5 13528 19876 27441 43242 30 20254 29758 41085 64743
1 19970 29341 40509 63835 40 24929 36627 50568 79687
2 32251 47384 65420 103090 50 29604 43496 60051 94631
3 43930 64544 89110 140423 60 34280 50365 69534 109575
4 59080 81016 111853 176261 70 38955 57234 79018 124519
5 71093 97489 134596 212100 80 43630 64102 88501 139463
6 83106 113962 157339 247939 90 48305 70971 97984

Type 441, 442 XXL

7 95118 130435 180082 100 52980 77840 107467
8 107131 146908 202824 120 62330 91578 126433
9 119144 163381 225567 140 71680 105315 145400
10 119144 163381 225567 160 81030 119053 164366
12 155182 212799 293796 180 90380 132791
14 179207 245745 200 99731 146528
16 203232 278690 220 109081 160266
18 227258 311636 240 118431 174003
20 251283 260 127781 187741
22 275308 280 137131
24 299334 300 146481
320 155831
340 165182
360 174532

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

LWN 482.01-E 03/19

 Type 441, 442 XXL
Capacities – Water

Capacities for water according to AD 2000-Merkblatt A2, based on set Capacities for water according to ASME Section VIII (UV), based on set
pressure plus 10 % overpressure at 20 °C (68 °F). Capacities at 1 bar pressure plus 10 % overpressure at 21 °C (70 °F). Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [103kg/h] US Units ASME Section VIII [US-G.P.M.]

DNI+O 200 x 300 250 x 350 300 x 400 400 x 500 DNI+O 200 x 300 250 x 350 300 x 400 400 x 500
Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20" Valve size 8" x 12" 10" x 14" 12" x 16" 16" x 20"
Act. Orifice dia. d0 [mm] 165 200 235 295 Act. Orifice dia. d0 [inch] 6.5 7.87 9.25 11.61
Act. Orifice area A0 [mm2] 21382 31416 43374 68349 Act. Orifice area A0 [inch2] 33.14 48.69 67.23 105.94
LEOL*) [inch2] 26.565 39.031 53.887 84.916 LEOL*) [inch2] 26.565 39.031 53.887 84.916
Set pressure [bar] Capacities [103kg/h] Set pressure [psig] Capacities [US-G.P.M.]
0.1 272 372 513 808 15 2780 4084 5639 8886
0.2 334 455 628 990 20 3142 4617 6374 10044
0.5 472 644 889 1400 30 3764 5530 7635 12031
1 639 871 1203 1896 40 4346 6386 8816 13893
2 903 1232 1702 2681 50 4859 7139 9857 15532
3 1106 1509 2084 3284 60 5323 7821 10797 17015
4 1278 1743 2406 3792 70 5749 8447 11662 18378
5 1428 1949 2690 4240 80 6146 9031 12468 19647
6 1565 2135 2947 4644 90 6519 9578 13224
Type 441, 442 XXL

7 1690 2306 3183 100 6872 10096 13939

8 1807 2465 3403 120 7528 11060 15270
9 1916 2614 3610 140 8131 11946 16493
10 2020 2756 3805 160 8692 12771 17632
12 2213 3019 4168 180 9220 13546
14 2390 3261 200 9718 14279
16 2555 3486 220 10193 14975
18 2710 3697 240 10646 15641
20 2857 260 11081 16280
22 2996 280 11499
24 3129 300 11902
320 12293
340 12671
360 13039

*) LEOL = LESER Effective Orifice liquids please refer to page 00/12

How to use capacity-sheets refer to page 00/09

03/20 LWN 482.01-E

Type 441, 442 XXL
h = Lift [mm]
Determination of coefficent of discharge d0 = Flow diameter [mm] of selected safety
in case of lift restriction or back pressure valve, refer to table article numbers
h/d0 = Ratio of lift / flow diameter
pa0 = Back pressure [bara]
p0 = Set pressure [bara]
pa0 / p0 = Ratio of back pressure / set pressure
Kdr = Coefficient of discharge
acc. to DIN EN ISO 4126-1
αw = Coefficient of discharge
acc. to AD 2000-Merkblatt A2
Diagram for evaluation of ratio of lift / flow diameter (h/d0) Kb = Back pressure correction factor
in reference to the coefficient of discharge (Kdr / αw) acc. to API 520 topic 3.3

How to use please refer to page 00/08

Kdr = αw = f (h/d0)
0.800

DN 200 – 400 S/G

0.700

DN 200 welded S/G

0.600

0.500

0.400
Coefficient of discharge Kdr / αw

DN 250 – 400, L

0.300
DN 200 welded L

0.200

Type 441, 442 XXL

0.100

0
0 0.050 0.100 0.150 0.200 0.250 0.300
0.243
Ratio of lift / flow diameter h / d0

Diagram for evaluation of coefficient of discharge (Kdr / αw) or Kb

in reference to the ratio of back pressure / set pressure (pa0 / p0)

Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0)

0.8

0.7 1.0

0.9
0.6
0.8
0.5 0.7

0.6
Back pressure correction factor Kb

0.4
Coefficient of discharge Kdr / αw

0.5
0.3
0.4

0.2 0.3

0.2
0.1
0.1

0 0
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
0.91
Ratio of back pressure / set pressure pa0 / p0

LWN 482.01-E 03/21

 Type 441, 442 XXL
Type 441, 442 XXL

03/22 LWN 482.01-E

 Type
Type 444 DIN
Packed lever H4
Closed bonnet
444 DIN
Conventional design

Flanged Safety Relief Valves

– spring loaded

Contents Chapter/Page
Materials
• Conventional design 04/02
How to order
• Numbering system 04/04
• Article numbers 04/06
Dimensions and weights
• Metric Units 04/07
• US Units 04/07
Pressure temperature ratings
• Metric Units 04/08
• US Units 04/08

Type 444 DIN

Flange drillings and facings 04/09
Order information – Spare parts 04/10
Available options 04/11
Approvals 04/12
Capacities
• Steam [Metric Units + US Units] 04/13
• Air [Metric Units + US Units] 04/14
• Water [Metric Units + US Units] 04/15
Determination of coefficient 04/16
of discharge Kdr /α w

LWN 482.01-E 04/01

 Type 444 DIN
Conventional design

40 Cap H2

18 Adjusting screw

19 Lock nut

16 Upper spring plate

54 Spring

12 Spindle

9 Bonnet

14 Split ring

17 Lower spring plate

Type 444 DIN

8 Guide with bushing

67 O-ring
68 Clamp
60 O-ring
22 Lift stopper
57 Pin
61 Ball

7 Disc

5 Seat

1 Body

04/02 LWN 482.01-E

Type 444 DIN
Conventional design

Materials
Item Component Type 4444 DIN

1.4404
1 Body
SA 479 316L
1.4404
5 Seat
316L
1.4404
7 Disc
316L
1.4404
Guide
316L
8
PTFE +15% glass
with bushing
PTFE +15% glass
1.4404
9 Bonnet
SA 479 316L
1.4404
12 Spindle
316L
1.4404
14 Split ring
316L
1.4404
16 / 17 Spring plate
316L
Adjusting screw 1.4404, PTFE + 15% glass
18
with bushing 316L, PTFE + 15% glass
1.4404
19 Lock nut
316L
1.4404
22 Lift stopper
316L
1.4404
40 Cap H2
316L

Type 444 DIN

1.4310
54 Spring
Stainless steel
1.4310
57 Pin
302
EPDM-FDA
60 O-ring
EPDM-FDA
1.4401
61 Ball
316
EPDM-FDA
67 O-ring
EPDM-FDA
1.4401
68 Clamp
316

Please notice:

– Modifications reserved by LESER.

– LESER can upgrade materials without notice.
– Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 04/03

 Type 444 DIN
How to order – Example for Numbering system

1 Article Number
2 Set Pressure
3 Connections

4444.3644 5 barg H45

Please state unit (in gauge)! Please refer to page 04/09

1 2 3 4
Please do not exceed the pressure
444 4 . 364 4 range defined in the spring charts.

1 Valve Type 444 DIN

Type 444 – with closed bonnet

2 Material code

Code Body material

4 1.4404 (316L)

3 Valve code
Identifies valve size and body
material, refer to page 04/09.
Type 444 DIN

Code Lifting lever

2 screwed cap H2
4 packed lever H4

04/04 LWN 482.01-E

Type 444 DIN

4 Options
5 Documentation
6
Code and Medium

J26 H01 L30 2.0

Type 444 DIN Option code Please select requested documentation:

1 2
• Detachable lifting aid J26 2 . 0
Inspections, tests: Option Code
• Adaptor for lift indicator DIN EN 10204-3.2: TÜV-Nord
– Lifting device J39 Certificate for test pressure M33 1 Code
– Bonnet J38
1. ASME Section VIII
• Lift indicator J93 LESER CGA (Certificate H03 2. CE / VdTUEV
• Test gag for Global Application) 3. ASME Section VIII
- cap H2 J70 - Inspection certificate 3.1 acc. + CE / VdTUEV
- packed lever H4 J69 to DIN EN 10204
• Seat 1.4404 / 316L stellited L61 - Declaration of conformity acc.
to PED 97/23/EC Medium
2
Option code applies only .1 Gases
if not standard Material test certificate: .2 Liquids
DIN EN 10204-3.1 .3 Steam
.0 Steam / Gases / Liquids
Part Option code (valid only for CE / VdTUEV)
Body H01

Type 444 DIN

Bonnet L30
Cap / lever cover L31
Disc L23

LWN 482.01-E 04/05

 Type 444 DIN
How to order – Article numbers

Type 444
Cap H2
Closed bonnet
Type 444 DIN

Conventional design
Type 444
Packed lever H4
Closed bonnet
Conventional design

Article numbers
DNI 25 25 50 65 80 80
DNo 50 80 80 100 100 100
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] 0.1 – 6.8 6.81 – 16
see page 04/08
Set pressure range S/G/L [psig] 1.5 – 98.6 98.61 – 232
Body material: 1.4404 (316L)
Bonnet H2 Art.-No. 4444. 3642 3662 3672 3682 3692 3702
closed H4 Art.-No. 4444. 3644 3664 3674 3684 3694 3704

04/06 LWN 482.01-E

Type 444 DIN
Dimensions and weights

Metric Units
DNI 25 40 50 65 80 80
DNo 50 80 80 100 100 100
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] see page 04/08 0.1 – 6.8 6.81 – 16

Weight [kg] 7 13 14 23 24 24
Center to face Inlet a 85 110 110 125 125 125
[mm] Outlet b 90 128 128 160 160 160
Height (H4) [mm] Standard H max. 308 519 519 631 631 631

Body material: 1.4404 (316L)

DIN Flange Inlet PN 16
Outlet PN 16

US Units
DNI 25 40 50 65 80 80
DNo 50 80 80 100 100 100
Actual Orifice diameter d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Actual Orifice area A0 inch2] 0.644 1.667 2.576 4.383 6.666 6.666
Set pressure range S/G/L [psig] see page 04/08 1.5 – 98.6 98.61 – 232

Weight [Ibs] 16 29 31 51 53 53
Center to face Inlet a 33/8 45/16 45/16 415/16 415/16 415/16

Type 444 DIN

[inch] Outlet b 31/2 51/16 51/16 65/16 65/16 65/16
Height (H4) [inch] Standard H max. 121/ 8 207/ 16 207/16 2013/ 16 2013/16 2013/16

Body material: 1.4404 (316L)

DIN Flange Inlet PN 16
Outlet PN 16

Conventional design

LWN 482.01-E 04/07

 Type 444 DIN
Pressure temperature ratings

Metric Units
DNI 25 40 50 65 80 80
DNO 50 80 80 100 100 100
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Body material: 1.4404 (316L)
DIN Flange Inlet PN 16
Outlet PN 16
Minimum
set pressure p [barg] S/G/L 0.1 0.1 0.1 0.1 0.1 6.81

Maximum
set pressure p [barg] S/G/L 16 16 16 16 6.8 16

Temperature min. [°C] -45

acc. to DIN EN max. [°C] +200
Temperature min. [°C] -45
acc. to ASME max. [°C] +200

US Units
DNI 25 40 50 65 80 80
DNO 50 80 80 100 100 100
Actual Orifice diameter d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Actual Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
Body material: 1.4404 (316L)
DIN Flange Inlet PN 16
Outlet PN 16
Minimum
set pressure p [psig] S/G/L 1.5 1.5 1.5 1.5 1.5 98.61
Type 444 DIN

Maximum
set pressure p [psig] S/G/L 232 232 232 232 98.6 232

Temperature min. [°F] -49

acc. to DIN EN max. [°F] +392
Temperature min. [°F] -49
acc. to ASME max. [°F] +392

04/08 LWN 482.01-E

Type 444 DIN
Flange drillings and facings

Flange drillings
DNI 25 40 50 65 80
DNO 50 80 80 100 100
Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4"
Actual Orifice diameter d0 [mm] 23 37 46 60 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301
Body material: 1.4404 (316L)
PN 10 – – – – –
PN 16
DIN EN 1092 * * * * *
PN 25 – – – – –
Inlet
PN 40 – – – – –
CL150
ASME B16.5 Please use Type 444 ANSI
CL300
PN 10 – – – – –
PN 16
DIN EN 1092 * * * * *
PN 25 – – – – –
Outlet
PN 40 – – – – –
CL150
ASME B16.5 Please use Type 444 ANSI
CL300

Flange facings
Indication Standard Inlet Outlet Remark
General
Flange undrilled – H38 H39
Lens seal form L DIN 2696
J11 J12
(without sealing lens) LWN 313.35

Type 444 DIN

Acc. to DIN EN 1092
Inlet Outlet Remark
Flange facing Rz-data according to
PN 10 – PN 40 PN 10 – PN 40
(see also LWN 313.40) DIN EN 1092 in μm
Type B1 Facing: Rz = 12.5 – 50
Raised face * *
Type B2 L36 L38 Facing: Rz = 3.2 – 12.5
Tongue face C1) H94 H92
Steel flanges only

Groove face D1) H93 H91

Male face E H96 H98
Female face F H97 H99
O-ring male face G J01 J02
O-ring female face H J03 J04
Acc. to ASME B16.5

Please use Type 444 ANSI

1) LESER manufactures the groove at flanged valves by milling. If a customer demands a turned surface in the soil of the groove according to DIN EN 1092-1
an additional option code is necessary: “S01: soil of the groove drilled”.

For signs and symbols refer to page 00/07

Note: Flange drillings and facings meet always the requirements of mentioned flange standards.
Flange thickness and outer diameter may vary from flange standard.

LWN 482.01-E 04/09

 Type 444 DIN
Order information – Spare parts

Spare parts
DNI 25 40 50 65 80 80
DNO 50 80 80 100 100 100
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] 0.1 – 6.8 6.81 – 16
see page 04/08
Set pressure range S/G/L [psig] 1.5 – 98.6 98.61 – 232
Disc (Item 7): Metal to metal seat Material-No. / Art.-No.
Disc
detachable lifting aid 1.4404 225.4149.9000 225.4349.9000 225.4449.9000 225.4549.9000 225.4649.9000 225.4649.9000

O-ring (Item 60 + 67) Material-No. / Art.-No.

O-ring EPDM “D” 502.0600.3041 502.1130.4041 502.1130.4041 502.1580.5041 502.1580.5041 502.1580.5041
FKM “L” 502.0600.3071 502.1130.4071 502.1130.4071 502.1580.5071 502.1580.5071 502.1580.5071
Ball (Item 61) Material-No. / Art.-No.
Ball ø [mm] 6 9 9 12 12 12
1.4401 510.0104.0000 510.0204.0000 510.0204.0000 510.0304.0000 510.0304.0000 510.0304.0000
Pin (Item 57) Material-No. / Art.-No.
Pin 1.4310 480.0505.0000 480.0705.0000 480.0705.0000 480.1005.0000 480.1005.0000 480.1005.0000
Type 444 DIN

04/10 LWN 482.01-E

Type 444 DIN
Available Options For further information refer to
“Accesoires and Options”, page 99/01

Screwed cap H2
H2

Packed lever H4
H4

Lift indicator bonnet

J38: Adaptor bonnet DN 25
J93: Lift indicator

Type 444 DIN

Lift indicator H4
DN 40 to DN 80
J39: Adaptor H4
J93: Lift indicator

LWN 482.01-E 04/11

 Type 444 DIN
Approvals

Approvals
DNI 25 40 50 65 80 80
DNO 50 80 80 100 100 100
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] 0.1 – 6.8 6.81 – 16
see page 04/08
Set pressure range S/G/L [psig] 1.5 – 98.6 98.61 – 232
Europe Coefficient of discharge Kdr
PED/DIN EN ISO 4126-1 Approval No. 072020111Z0008/0/08 Rev.3
S/G 0.7 0.55
L 0.48 0.48
Germany Coefficient of discharge α w
PED/AD 2000-Merkblatt A2 Approval No. TÜV SV 576
S/G 0.7 0.55
L 0.48 0.48
United States Coefficient of discharge K
ASME Sec. VIII Div. 1 Approval No. M37044 –
S/G 0.699 –
Approval No. M37055 M37055
L 0.521 0.521
Canada Coefficient of discharge K
Canada: CRN Approval No. For current approval no. see www.leser.com
S/G 0.699 –
L 0.521 0.521
China Coefficient of discharge α w
AQSIQ Approval No. For current approval no. see www.leser.com
S/G 0.7 0.55
Type 444 DIN

L 0.48 0.48
Russia Coefficient of discharge α w
GOST R / RTN Approval No. For current approval no. see www.leser.com
S/G 0.7 0.55
L 0.48 0.48
Kazakhstan Coefficient of discharge α w
GOST-K Approval No. For current approval no. see www.leser.com
S/G 0.7 0.55
L 0.48 0.48
Belarus Coefficient of discharge α w
GOSPROMNAZADOR Approval No. For current approval no. see www.leser.com
S/G 0.7 0.55
L 0.48 0.48
Classification societies
on request

04/12 LWN 482.01-E

Type 444 DIN
Capacities – Steam

Capacities for saturated steam according to AD 2000-Merkblatt A2, Capacities for saturated steam according to ASME Section VIII (UV),
based on set pressure plus 10 % overpressure. Capacities at 1 bar based on set pressure plus 10% overpressure. Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [kg/h] US Units ASME Section VIII [lb/h]

DNI 25 40 50 65 80 80 DNI 25 40 50 65 80 80
DNO 50 80 80 100 100 100 DNO 50 80 80 100 100 100
Act. Orifice dia. d0 [mm] 23 37 46 60 74 74 Act. Orifice dia. d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Act. Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301 Act. Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 4.779 LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 4.779

0.1 – 6.81– 1.5 – 98.61 –

Set pressure S/G [barg] Set pressure S/G [psig]
6.8 16 98.6 232

Set pressure [bar] Capacities [kg/h] Set pressure [psig] Capacities [lb/h]
0.1 112 274 405 720 1093 15 758 1962 3032 5159 7847
0.2 144 353 524 927 1417 20 874 2262 3496 5948 9047
0.5 223 546 822 1434 2221 30 1106 2862 4423 7525 11447
1 324 790 1209 2086 3262 40 1361 3522 5443 9261 14087
2 529 1285 2002 3413 5377 50 1616 4182 6463 10996 16726
3 699 1761 2770 4695 7237 60 1871 4842 7483 12732 19366
4 872 2256 3487 5932 9023 70 2126 5501 8503 14467 22006
5 1043 2700 4174 7101 10801 80 2381 6161 9523 16202 24646
6 1215 3143 4858 8266 12573 90 2636 6821 10543 17938 27285
7 1382 3575 5526 9402 11237 100 2891 7481 11563 19673 29925
8 1552 4015 6206 10559 12619 120 3401 8801 13604 23144 35205
9 1721 4455 6885 11714 14000 140 3911 10121 15644 26615 40484
10 1891 4894 7564 12868 15380 160 4421 11441 17684 30086 45764
12 2230 5772 8922 15179 18141 180 4931 12761 19724 33557 51043
14 2562 6631 10249 17437 20840 200 5441 14081 21764 37027 56323
16 2901 7507 11603 19740 23593 220 5951 15401 23804 40498 61602
230 6206 16060 24824 42234 64242

Type 444 DIN

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11
How to use capacity-sheets refer to page 00/09

LWN 482.01-E 04/13

 Type 444 DIN
Capacities – Air

Capacities for air according to AD 2000-Merkblatt A2, based on set Capacities for air according to ASME Section VIII (UV), based on set
pressure plus 10 % overpressure at 0 °C and 1013 mbar. Capacities pressure plus 10 % overpressure at 16 °C (60 °F). Capacities at 2.07 bar
at 1 bar (14.5 psig) and below are based on 0.1 bar (1.45 psig) over- (30 psig) and below are based on 0.207 bar (3 psig) overpressure.
pressure.

Metric Units AD 2000-Merkblatt A2 [mn3/h] US Units ASME Section VIII [S.C.F.M.]

DNI 25 40 50 65 80 80 DNI 25 40 50 65 80 80
DNO 50 80 80 100 100 100 DNO 50 80 80 100 100 100
Act. Orifice dia. d0 [mm] 23 37 46 60 74 74 Act. Orifice dia. d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Act. Orifice area A0 [mm2] 416 661 1075 1662 2827 6648 Act. Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 4.779 LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 4.779
0.1 – 6.81– 1.5 – 98.61 –
Set pressure S/G [barg] Set pressure S/G [psig]
6.8 16 98.6 232
Set pressure [bar] Capacities [mn3/h] Set pressure [psig] Capacities [S.C.F.M.]
0.1 129 316 466 829 1257 15 269 697 1077 1832 2786
0.2 167 409 607 1073 1640 20 310 803 1241 2112 3212
0.5 262 640 964 1683 2607 30 393 1016 1571 2672 4064
1 386 941 1440 2484 3884 40 483 1250 1933 3288 5002
2 639 1551 2416 4119 6489 50 574 1485 2295 3904 5939
3 853 2150 3382 5732 8835 60 664 1719 2657 4521 6876
4 1071 2772 4284 7289 11088 70 755 1953 3019 5137 7814
5 1289 3335 5155 8771 13341 80 845 2188 3381 5753 8751
6 1506 3899 6026 10252 15594 90 936 2422 3744 6369 9688
7 1724 4462 6897 11733 14023 100 1026 2656 4106 6985 10625
8 1942 5025 7767 13214 15793 120 1208 3125 4830 8218 12500
9 2159 5588 8638 14696 17564 140 1389 3594 5555 9450 14375
10 2377 6152 9509 16177 19334 160 1570 4062 6279 10682 16249
12 2812 7278 11250 19140 22875 180 1751 4531 7003 11915 18124
14 3248 8405 12991 22102 26416 200 1932 5000 7728 13147 19998
16 3683 9532 14733 25065 29956 220 2113 5468 8452 14380 21873
230 2204 5703 8814 14996 22810
Type 444 DIN

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09

04/14 LWN 482.01-E

Type 444 DIN
Capacities – Water

Capacities for water according to AD 2000-Merkblatt A2, based on set Capacities for water according to ASME Section VIII (UV), based on set
pressure plus 10 % overpressure at 20 °C (68 °F). Capacities at 1 bar pressure plus 10 % overpressure at 21 °C (70 °F). Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [103kg/h] US Units ASME Section VIII [US-G.P.M.]

DNI 25 40 50 65 80 80 DNI 25 40 50 65 80 80
DNO 50 80 80 100 100 100 DNO 50 80 80 100 100 100
Act. Orifice dia. d0 [mm] 23 37 46 60 74 74 Act. Orifice dia. d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Act. Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301 Act. Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
LEOL*) [inch2] 0.516 1.336 2.065 3.513 5.343 5.343 LEOL*) [inch2] 0.516 1.336 2.065 3.513 5.343 5.343
0.1 – 6.81 – 1.5 – 98.61 –
Set pressure L [barg] Set pressure L [psig]
6.8 16 98.6 232
Set pressure [bar] Capacities [103kg/h] Set pressure [psig] Capacities [US-G.P.M.]
0.1 4.54 11.8 18.2 30.9 47 15 54.1 140 216 368 560
0.2 5.56 14.4 22.2 37.8 57.6 20 61.1 158 245 416 633
0.5 7.87 20.4 31.5 53.5 81.4 30 73.2 190 293 498 758
1 10.6 27.6 42.6 72.5 110 40 84.6 219 338 576 875
2 15.1 39 60.2 102 156 50 94.6 245 378 643 979
3 18.4 47.7 73.8 126 191 60 104 268 414 705 1072
4 21.3 55.1 85.2 145 220 70 112 290 447 761 1158
5 23.8 61.6 95.3 162 246 80 120 310 478 814 1238
6 26.1 67.5 104 178 270 90 127 328 507 863 1313
7 28.2 72.9 113 192 292 100 134 346 535 910 1384
8 30.1 77.9 120 205 312 120 146 379 586 997 1516
9 31.9 82.7 128 217 331 140 158 409 633 1077 1638
10 33.7 87.2 135 229 349 160 169 438 677 1151 1751
12 36.9 95.5 148 251 382 180 179 464 718 1221 1857
14 39.8 103 159 271 412 200 189 489 756 1287 1958
16 42.6 110 170 290 441 220 198 513 793 1350 2053
230 203 525 811 1380 2099

Type 444 DIN

*) LEOL = LESER Effective Orifice liquids please refer to page 00/12
How to use capacity-sheets refer to page 00/09

LWN 482.01-E 04/15

 Type 444 DIN
h = Lift [mm]
Determination of coefficent of discharge d0 = Flow diameter [mm] of selected safety
in case of lift restriction or back pressure valve, refer to table article numbers
h/d0 = Ratio of lift / flow diameter
p a0 = Back pressure [bara]
p0 = Set pressure [bara]
pa0 / p0 = Ratio of back pressure / set pressure
Kdr = Coefficient of discharge
acc. to DIN EN ISO 4126-1
αw = Coefficient of discharge
acc. to AD 2000-Merkblatt A2
Diagram for evaluation of ratio of lift / flow diameter (h/d0) Kb = Back pressure correction factor
in reference to the coefficient of discharge (Kdr / αw) acc. to API 520 topic 3.3

How to use please refer to page 00/08

Kdr = αw = f (h/d0)
0.8

DN 25 S/G
0.7 DN 40 S/G
DN 65 S/G

0.6
DN 50 S/G DN 80 S/G

0.5
Coefficient of discharge Kdr / αw

0.4
DN 80 L
DN 25 L
0.3 DN 40 L
DN 65 L

0.2 DN 50 L

0.1

0
0 0.05 0.10 0.15 0.20 0.25 0.30 0.35
Ratio of lift / flow diameter h / d0

Diagram for evaluation of coefficient of discharge (Kdr / αw) or Kb

in reference to the ratio of back pressure / set pressure (pa0 / p0)
DN 80 (6.81 – 16 bar / 98.61 – 232 psig)

Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0) Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0)

Type 444 DIN

0.8 0.6

DN 25 1.0
0.7 1.0
DN 80 (0.1 – 6.8 bar) 0.5 0.9
(1.5 – 98.6 psig) 0.9
0.6 0.8
0.8
0.4 0.7
0.5 DN 40 – 65
0.7 DN 80 (6.81 – 16 bar)
(98.61 – 232 psig)
0.6
0.6
Back pressure correction factor Kb

Back pressure correction factor Kb

0.4 0.3
Coefficient of discharge Kdr / αw

Coefficient of discharge Kdr / αw

0.5
0.5
0.3 0.4
0.4 0.2
0.3
0.2 0.3

0.2 0.2
0.1
0.1
0.1 0.1

0 0 0 0
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
0.909 0.909
Ratio of back pressure / set pressure pa0 / p0 Ratio of back pressure / set pressure pa0 / p0

04/16 LWN 482.01-E

 Type
Type 444 ANSI
Packed lever H4
444 ANSI
Closed bonnet
Conventional design

Flanged Safety Relief Valves

– spring loaded

Contents Chapter/Page
Materials
• Conventional design 05/02
How to order
• Numbering system 05/04
• Article numbers 05/06
Dimensions and weights
• Metric Units 05/07
• US Units 05/07
Pressure temperature ratings
• Metric Units 05/08
• US Units 05/08
Flange drillings and facings 05/09
Order information – Spare parts 05/10
Available options 05/11
Approvals 05/12
Capacities
• Steam [Metric Units + US Units] 05/13
• Air [Metric Units + US Units] 05/14
• Water [Metric Units + US Units] 05/15
Type 444 ANSI

Determination of coefficient 05/16

of discharge Kdr /α w

LWN 482.01-E 05/01

 Type 444 ANSI
Conventional design

40 Cap H2

18 Adjusting screw

19 Lock nut

16 Upper spring plate

54 Spring

12 Spindle

9 Bonnet

14 Split ring

17 Lower spring plate

8 Guide with bushing

67 O-ring
68 Clamp
60 O-ring
22 Lift stopper
57 Pin
Type 444 ANSI

61 Ball

7 Disc

5 Seat

1 Body

05/02 LWN 482.01-E

Type 444 ANSI
Conventional design

Materials
Item Component Type 4444 ANSI

1.4404
1 Body
SA 479 316L
1.4404
5 Seat
316L
1.4404
7 Disc
316L
1.4404
Guide
316L
8
PTFE +15% glass
with bushing
PTFE +15% glass
1.4404
9 Bonnet
SA 479 316L
1.4404
12 Spindle
316L
1.4404
14 Split ring
316L
1.4404
16 / 17 Spring plate
316L
Adjusting screw 1.4404, PTFE + 15% glass
18
with bushing 316L, PTFE + 15% glass
1.4404
19 Lock nut
316L
1.4404
22 Lift stopper
316L
1.4404
40 Cap H2
316L
1.4310
54 Spring
Stainless steel
1.4310
57 Pin
302
EPDM-FDA
60 O-ring
EPDM-FDA
1.4401
61 Ball
316
EPDM-FDA
67 O-ring
EPDM-FDA
Type 444 ANSI

1.4401
68 Clamp
316

Please notice:

– Modifications reserved by LESER.

– LESER can upgrade materials without notice.
– Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 05/03

 Type 444 ANSI
How to order – Example for Numbering system

1 Article Number
2 Set Pressure
3 Connections

4444.8934 5 barg H45

Please state unit (in gauge)! Please refer to page 05/09

1 2 3 4
Please do not exceed the pressure
444 4 . 893 4 range defined in the spring charts.

1 Valve Type 444 ANSI

Type 444 – with closed bonnet

2 Material code

Code Body material

4 1.4404 (316L)

3 Valve code
Identifies valve size and body
material, refer to page 05/06.

Code Lifting lever

2 Screwed cap H2
4 Packed lever H3
Type 444 ANSI

05/04 LWN 482.01-E

Type 444 ANSI

4 Options
5 Documentation
6
Code and Medium

J26 H01 L30 2.0

Type 444 ANSI Option code Please select requested documentation:

1 2

• Detachable lifting aid J26 Inspections, tests: Option Code 2 . 0

• Adaptor for lift indicator DIN EN 10204-3.2: TÜV-Nord
– Lifting device J39 Certificate for test pressure M33 1 Code
– Bonnet J38 1. ASME Section VIII
• Lift indicator J93 LESER CGA (Certificate H03 2. CE / VdTUEV
• Test gag for Global Application) 3. ASME Section VIII
- Inspection certificate 3.1 acc. + CE / VdTUEV
- cap H2 J70
to DIN EN 10204
- packed lever H4 J69
- Declaration of conformity acc.
• Seat 1.4404 / 316L stellited L61
to PED 97/23/EC Medium
2
Option code applies only .1 Gases
Material test certificate: .2 Liquids
if not standard
DIN EN 10204-3.1 .3 Steam
.0 Steam / Gases / Liquids
Part Option code (valid only for CE / VdTUEV)
Body H01
Bonnet L30
Cap / lever cover L31
Disc L23

Type 444 ANSI

LWN 482.01-E 05/05

 Type 444 ANSI
How to order – Article numbers

Type 444
Cap H2
Closed bonnet
Conventional design
Type 444
Packed lever H4
Closed bonnet
Conventional design
Type 444 ANSI

Article numbers
Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x4" 3" x 4" 3" x 4 "
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] 0.1 – 6.8 6.81 – 16
see page 05/08
Set pressure range S/G/L [psig] 1.5 – 98.6 98.61 – 232
Body material: 1.4404 (316L)
Bonnet H2 Art.-No. 4444. 8902 8922 8932 8942 8952 8962
closed H4 Art.-No. 4444. 8904 8924 8934 8944 8954 8964

05/06 LWN 482.01-E

Type 444 ANSI
Dimensions and weights

Metric Units
Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4" 3" x 4"
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] see page 05/08 0.1 – 6.8 6.81 – 16

Weight [kg] 7 13 14 23 24 24
Center to face Inlet a 85 110 110 125 125 125
[mm] Outlet b 90 128 128 160 160 160
Height (H4) [mm] Standard H max. 308 519 519 631 631 631

Body material: 1.4404 (316L)

ANSI Flange Inlet CL150
Class Outlet CL150

US Units
DNI 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4" 3" x 4"
Actual Orifice diameter d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Actual Orifice area A0 inch2] 0.644 1.667 2.576 4.383 6.666 6.666
Set pressure range S/G/L [psig] see page 05/08 1.5 – 98.6 98.61 – 232

Weight [Ibs] 16 29 31 51 53 53
Center to face Inlet a 3 3/8 4 5/16 4 5/16 4 15/16 4 15/16 4 15/16
[inch] Outlet b 3 1/2 5 1/16 5 1/16 6 5/16 6 5/16 6 5/16
Height (H4) [inch] Standard H max. 12 1/ 20 7/ 20 7/ 20 13/ 20 13/ 20 13/16
8 16 16 16 16

Body material: 1.4404 (316L)

ANSI Flange Inlet CL150
Class Outlet CL150

Type 444 ANSI

Conventional design

LWN 482.01-E 05/07

 Type 444 ANSI
Pressure temperature ratings

Metric Units
Valve size 1" x 2" 11/2" x 2" 2" x 3 " 21/2" x 4" 3" x 4" 3" x 4 "
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Body material: 1.4404 (316L)
ANSI Flange Inlet CL150
Class1) Outlet CL150
Minimum
p [barg] S/G/L 0.1 0.1 0.1 0.1 0.1 6.81
set pressure
Maximum
p [barg] S/G/L 16 16 16 16 6.8 16
set pressure
Temperature min. [°C] -45
acc. to DIN EN max. [°C] +200
Temperature min. [°C] -45
acc. to ASME max. [°C] +200

US Units
Valve size 1" x 2" 11/2" x 2" 2" x 3 " 21/2" x 4" 3" x 4" 3" x 4 "
Actual Orifice diameter d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Actual Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
Body material: 1.4404 (316L)
ANSI Flange Inlet CL150
Class1) Outlet CL150
Minimum
p [psig] S/G/L 1.5 1.5 1.5 1.5 1.5 98.61
set pressure
Maximum
p [psig] S/G/L 232 232 232 232 98.6 232
set pressure
Temperature min. [°F] -49
acc. to DIN EN max. [°F] +392
Temperature min. [°F] -49
acc. to ASME max. [°F] +392

1) For flange rating class 150 the pressure temperature ratings according to ASME ANSI B 16.34 apply.
Type 444 ANSI

05/08 LWN 482.01-E

Type 444 ANSI
Flange drillings and facings

Flange drillings
DNI 25 40 50 65 80
DNO 50 80 80 100 100
Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4"
Actual Orifice diameter d0 [mm] 23 37 46 60 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301
Body material: 1.4404 (316L)
PN 10
PN 16
DIN EN 1092 Please use Type 444 DIN
PN 25
Inlet
PN 40
CL150
ASME B16.5 * * * * *
CL300 – – – – –
PN 10
PN 16
DIN EN 1092 Please use Type 444 DIN
PN 25
Outlet
PN 40
CL150
ASME B16.5 * * * * *
CL300 – – – – –

Flange facings
Indication Standard Inlet Outlet Remark
General
Flange undrilled – H38 H39
Acc. to DIN EN 1092

Please use Type 444 ANSI

Acc. to ASME B16.5

Smooth finish1) Serrated finish RTJ-groove
Body material Inlet Outlet Inlet Outlet Inlet Outlet Inlet Outlet
Option code Option code RTJ-Class Option code RTJ-Class Option code
1.4404 all all L52 L53 CL150 H62 CL150 H63
* *
1) Smooth finish is not defined in the effective standards.
Type 444 ANSI

For signs and symbols refer to page 00/07

Note: Flange drillings and facings meet always the requirements of mentioned flange standards.
Flange thickness and outer diameter may vary from flange standard.

LWN 482.01-E 05/09

 Type 444 ANSI
Order information – Spare parts

Spare parts
Valve size 1" x 2" 11/2" x 2" 2" x 3" 21/2" x 4" 3" x 4" 3" x 4"
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
Actual Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] 0.1 – 6.8 6.81 – 16
see page 05/08
Set pressure range S/G/L [psig] 1.5 – 98.6 98.61 – 232
Disc (Item 7): Metal to metal seat Material-No. / Art.-No.
Disc
detachable lifting aid 1.4404 225.4149.9000 225.4349.9000 225.4449.9000 225.4549.9000 225.4649.9000 225.4649.9000

O-ring (Item 60 + 67) Material-No. / Art.-No.

Gasket EPDM “D” 502.0600.3041 502.1130.4041 502.1130.4041 502.1580.5041 502.1580.5041 502.1580.5041
FKM “L” 502.0600.3071 502.1130.4071 502.1130.4071 502.1580.5071 502.1580.5071 502.1580.5071
Ball (Item 61) Material-No. / Art.-No.
Ball ø [mm] 6 9 9 12 12 12
1.4401 510.0104.0000 510.0204.0000 510.0204.0000 510.0304.0000 510.0304.0000 510.0304.0000
Pin (Item 57) Material-No. / Art.-No.
Pin 1.4310 480.0505.0000 480.0705.0000 480.0705.0000 480.1005.0000 480.1005.0000 480.1005.0000
Type 444 ANSI

05/10 LWN 482.01-E

Type 444 ANSI
Available Options For further information refer to
“Accesoires and Options”, page 99/01

Screwed cap H2
H2

Packed lever H4
H4

Lift indicator bonnet

J38: Adaptor bonnet valve size 1"
J93: Lift indicator

Lift indicator H4
Valve size 11/2" up to 3"
J39: Adaptor H4
Type 444 ANSI

J93: Lift indicator

LWN 482.01-E 05/11

 Type 444 ANSI
Approvals

Approvals
Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4" 3" x 4"
Actual Orifice diameter d0 [mm] 23 37 46 60 74 74
2
Actual Orifice area A0 [mm ] 416 1075 1662 2827 4301 4301
Set pressure range S/G/L [barg] 0.1 – 6.8 6.81 – 16
see page 05/08
Set pressure range S/G/L [psig] 1.5 – 98.6 98.61 – 232
Europe Coefficient of discharge Kdr
PED/DIN EN ISO 4126-1 Approval No. 072020111Z0008/0/08-2
S/G 0.7 0.55
L 0.48 0.48
Germany Coefficient of discharge α w
PED/AD 2000-Merkblatt A2 Approval No. TÜV SV 576
S/G 0.7 0.55
L 0.48 0.48
United States Coefficient of discharge K
ASME Sec. VIII Div. 1 Approval No. M37044 –
S/G 0.699 –
Approval No. M37055 M37055
L 0.521 0.521
Canada Coefficient of discharge K
Canada: CRN Approval No. For current approval no. see www.leser.com
S/G 0.699 –
L 0.521 0.521
China Coefficient of discharge α w
AQSIQ Approval No. For current approval no. see www.leser.com
S/G 0.7 0.55
L 0.48 0.48
Russia Coefficient of discharge α w
GOST R / RTN Approval No. For current approval no. see www.leser.com
S/G 0.7 0.55
L 0.48 0.48
Kazakhstan Coefficient of discharge α w
GOST-K Approval No. For current approval no. see www.leser.com
S/G 0.7 0.55
L 0.48 0.48
Belarus Coefficient of discharge α w
Type 444 ANSI

PROMATONAZDOR Approval No. For current approval no. see www.leser.com

S/G 0.7 0.55
L 0.48 0.48
Classification societies
on request

05/12 LWN 482.01-E

Type 444 ANSI
Capacities – Steam

Capacities for saturated steam according to AD 2000-Merkblatt A2, Capacities for saturated steam according to ASME Section VIII (UV),
based on set pressure plus 10 % overpressure. Capacities at 1 bar based on set pressure plus 10% overpressure. Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [kg/h] US Units ASME Section VIII [lb/h]

Valve size 1" x 2" 11/2" x 3" 2"x 3" 21/2" x 4" 3"x 4"1) 3"x 4"2) Valve size 1" x 2" 11/2" x 3" 2"x 3" 21/2" x 4" 3"x 4"1) 3"x 4"2)
Act. Orifice dia. d0 [mm] 23 37 46 60 74 74 Act. Orifice dia. d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Act. Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301 Act. Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 4.779 LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 4.779
0.1 – 6.81– 1.5 – 98.61 –
Set pressure S/G [barg] Set pressure S/G [psig]
6.8 16 98.6 232
Set pressure [bar] Capacities [kg/h] Set pressure [psig] Capacities [lb/h]
0.1 112 274 405 720 1093 15 758 1962 3032 5159 7847
0.2 144 353 524 927 1417 20 874 2262 3496 5948 9047
0.5 223 546 822 1434 2221 30 1106 2862 4423 7525 11447
1 324 790 1209 2086 3262 40 1361 3522 5443 9261 14087
2 529 1285 2002 3413 5377 50 1616 4182 6463 10996 16726
3 699 1761 2770 4695 7237 60 1871 4842 7483 12732 19366
4 872 2256 3487 5932 9023 70 2126 5501 8503 14467 22006
5 1043 2700 4174 7101 10801 80 2381 6161 9523 16202 24646
6 1215 3143 4858 8266 12573 90 2636 6821 10543 17938 27285
7 1382 3575 5526 9402 11237 100 2891 7481 11563 19673 29925
8 1552 4015 6206 10559 12619 120 3401 8801 13604 23144 35205
9 1721 4455 6885 11714 14000 140 3911 10121 15644 26615 40484
10 1891 4894 7564 12868 15380 160 4421 11441 17684 30086 45764
12 2230 5772 8922 15179 18141 180 4931 12761 19724 33557 51043
14 2562 6631 10249 17437 20840 200 5441 14081 21764 37027 56323
16 2901 7507 11603 19740 23593 220 5951 15401 23804 40498 61602
230 6206 16060 24824 42234 64242

*)
LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11
How to use capacity-sheets refer to page 00/09

Type 444 ANSI

LWN 482.01-E 05/13

 Type 444 ANSI
Capacities – Air

Capacities for air according to AD 2000-Merkblatt A2, based on set Capacities for air according to ASME Section VIII (UV), based on set
pressure plus 10 % overpressure at 0 °C and 1013 mbar. Capacities pressure plus 10 % overpressure at 16 °C (60 °F). Capacities at 2.07 bar
at 1 bar (14.5 psig) and below are based on 0.1 bar (1.45 psig) over- (30 psig) and below are based on 0.207 bar (3 psig) overpressure.
pressure

Metric Units AD 2000-Merkblatt A2 [mn3/h] US Units ASME Section VIII [S.C.F.M.]

Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4"1) 3" x 4"2) Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4"1 3" x 4"2)
Act. Orifice dia. d0 [mm] 23 37 46 60 74 74 Act. Orifice dia. d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Act. Orifice area A0 [mm2] 416 1075 662 2827 4301 4301 Act. Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 – LEOS/G*) [inch2] 0.462 1.195 1.847 3.142 4.779 4.779
0.1 – 6.81 – 1.5 – 98.61 –
Set pressure S/G [barg] Set pressure S/G [psig]
6.8 16 98.6 232
Set pressure [bar] Capacities [mn3/h] Set pressure [psig] Capacities [S.C.F.M.]
0.1 129 316 466 829 1257 15 269 697 1077 1832 2786
0.2 167 409 607 1073 1640 20 310 803 1241 2112 3212
0.5 262 640 964 1683 2607 30 393 1016 1571 2672 4064
1 386 941 1440 2484 3884 40 483 1250 1933 3288 5002
2 639 1551 2416 4119 6489 50 574 1485 2295 3904 5939
3 853 2150 3382 5732 8835 60 664 1719 2657 4521 6876
4 1071 2772 4284 7289 11088 70 755 1953 3019 5137 7814
5 1289 3335 5155 8771 13341 80 845 2188 3381 5753 8751
6 1506 3899 6026 10252 15594 90 936 2422 3744 6369 9688
7 1724 4462 6897 11733 14023 100 1026 2656 4106 6985 10625
8 1942 5025 7767 13214 15793 120 1208 3125 4830 8218 12500
9 2159 5588 8638 14696 17564 140 1389 3594 5555 9450 14375
10 2377 6152 9509 16177 19334 160 1570 4062 6279 10682 16249
12 2812 7278 11250 19140 22875 180 1751 4531 7003 11915 18124
14 3248 8405 12991 22102 26416 200 1932 5000 7728 13147 19998
16 3683 9532 14733 25065 29956 220 2113 5468 8452 14380 21873
230 2204 5703 8814 14996 22810

*) LEOS/G = LESER Effective Orifice steam/gas please refer to page 00/11

How to use capacity-sheets refer to page 00/09
Type 444 ANSI

05/14 LWN 482.01-E

Type 444 ANSI
Capacities – Water

Capacities for water according to AD 2000-Merkblatt A2, based on set Capacities for water according to ASME Section VIII (UV), based on set
pressure plus 10 % overpressure at 20 °C (68 °F). Capacities at 1 bar pressure plus 10 % overpressure at 21 °C (70 °F). Capacities at 2.07 bar
(14.5 psig) and below are based on 0.1 bar (1.45 psig) overpressure. (30 psig) and below are based on 0.207 bar (3 psig) overpressure.

Metric Units AD 2000-Merkblatt A2 [103kg/h] US Units ASME Section VIII [US-G.P.M.]

Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4"1) 3" x 4"2) Valve size 1" x 2" 11/2" x 3" 2" x 3" 21/2" x 4" 3" x 4"1) 3" x 4"2)
Act. Orifice dia. d0 [mm] 23 37 46 60 74 74 Act. Orifice dia. d0 [inch] 0.91 1.46 1.81 2.36 2.91 2.91
Act. Orifice area A0 [mm2] 416 1075 1662 2827 4301 4301 Act. Orifice area A0 [inch2] 0.644 1.667 2.576 4.383 6.666 6.666
LEOL*) [inch2] 0.516 1.336 2.065 3.513 5.343 5.343 LEOL*) [inch2] 0.516 1.336 2.065 3.513 5.343 5.343
0.1 – 6.81 – 1.5 – 98.61 –
Set pressure L [barg] Set pressure L [psig]
6.8 16 98.6 232
Set pressure [bar] Capacities [103kg/h] Set pressure [psig] Capacities [US-G.P.M.]
0.1 4.54 11.8 18.2 30.9 47.0 15 54.1 140 216 368 560
0.2 5.56 14.4 22.2 37.8 57.6 20 61.1 158 245 416 633
0.5 7.87 20.4 31.5 53.5 81.4 30 73.2 190 293 498 758
1 10.6 27.6 42.6 72.5 110 40 84.6 219 338 576 875
2 15.1 39 60.2 102 156 50 94.6 245 378 643 979
3 18.4 47.7 73.8 126 191 60 104 268 414 705 1072
4 21.3 55.1 85.2 145 220 70 112 290 447 761 1158
5 23.8 61.6 95.3 162 246 80 120 310 478 814 1238
6 26.1 67.5 104 178 270 90 127 328 507 863 1313
7 28.2 72.9 113 192 292 100 134 346 535 910 1384
8 30.1 77.9 120 205 312 120 146 379 586 997 1516
9 31.9 82.7 128 217 331 140 158 409 633 1077 1638
10 33.7 87.2 135 229 349 160 169 438 677 1151 1751
12 36.9 95.5 148 251 382 180 179 464 718 1221 1857
14 39.8 103 159 271 412 200 189 489 756 1287 1958
16 42.6 110 170 290 441 220 198 513 793 1350 2053
230 203 525 811 1380 2099

*) LEOL = LESER Effective Orifice liquids please refer to page 00/12

How to use capacity-sheets refer to page 00/09

Type 444 ANSI

LWN 482.01-E 05/15

 Type 444 ANSI
h = Lift [mm]
Determination of coefficent of discharge d0 = Flow diameter [mm] of selected safety
in case of lift restriction or back pressure valve, refer to table article numbers
h/d0 = Ratio of lift / flow diameter
p a0 = Back pressure [bara]
p0 = Set pressure [bara]
pa0 / p0 = Ratio of back pressure / set pressure
Kdr = Coefficient of discharge
acc. to DIN EN ISO 4126-1
αw = Coefficient of discharge
acc. to AD 2000-Merkblatt A2
Diagram for evaluation of ratio of lift / flow diameter (h/d0) Kb = Back pressure correction factor
in reference to the coefficient of discharge (Kdr / αw) acc. to API 520 topic 3.3

How to use please refer to page 00/08

Kdr = αw = f (h/d0)
0.8

1" S/G
0.7 11/2" S/G
21/2" S/G

0.6
2" S/G 3" S/G

0.5
Coefficient of discharge Kdr / αw

0.4
3" L
1" L
0.3 11/2" L
21/2" L

0.2 2" L

0.1

0
0 0.05 0.1 0.15 0.20 0.25 0.3 0,35
Ratio of lift / flow diameter h / d0

Diagram for evaluation of coefficient of discharge (Kdr / αw) or Kb

in reference to the ratio of back pressure / set pressure (pa0 / p0)
3" (6.81 – 16 bar / 98.61 – 232 psig)

Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0) Kdr = αw = f (pa0/p0) and Kb = f (pa0/p0)

0.8 0.6

1" 1.0
0.7 1.0
3" (0.1 – 6.8 bar) 0.5 0.9
(1.5 – 98.6 psig) 0.9
0.6 0.8
0.8
0.4 0.7
0.5 1 1/2" – 2 1/2"
0.7
3" (6.81 – 16 bar)
(98.61 – 232 psig)
0.6
0.6
Back pressure correction factor Kb
Back pressure correction factor Kb

0.4 0.3
Coefficient of discharge Kdr / αw
Coefficient of discharge Kdr / αw

0.5
Type 444 ANSI

0.5
0.3 0.4
0.4 0.2
0.3
0.2 0.3

0.2
0.2 0.1
0.1
0.1 0.1

0 0 0 0
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.2 0.3 0.4 0.5 0.7 0.6 0.8 0.9 1.0
0.909 0.909
Ratio of back pressure / set pressure pa0 / p0 Ratio of back pressure / set pressure pa0 / p0

05/16 LWN 482.01-E

 Accessories
and Options
Contents Chapter/Page

Overview 99/02
Caps and Levers 99/04
Caps and Levers bolted 99/06
Metal seat 99/08
Soft seal disc 99/10
Soft seal 99/12
Balanced bellows 99/14
High temperature equipment 99/16
Elastomer bellows 99/17
Disc 99/18
Heating jacket 99/20
O-ring damper 99/22
Lift indicator 99/24
Lift restriction 99/25

Options

LWN 482.01-E 99/01

 Accessories and Options
Overview

Options
Type 441, 442 DIN 441, 442 XXL 444 DIN 441 FN DIN 455/456 457/458
441, 442 ANSI 444 ANSI 441 FN ANSI
442 FN DIN
Option code 442 FN ANSI
Disc (Item 7)
Disc with detachable lifting aid J26 ✓ * * ✓ * *
Bull race disc J24 ✓ ✓ ✓ ✓ * *
Disc with detachable lifting aid,
J25 ✓ ✓ ✓ ✓ * *
Bull race, stellited
Type of sealing (Item 5 and 7)
Metal seat Disc 1.4404 L44 ✓ ✓ ✓ ✓ ✓ ✓
Disc 1.4404 stellited J25 ✓ ✓ ✓ ✓ ✓ ✓
CR “K” J21 ✓ on request – ✓ ✓ ✓
NBR “N” J30 ✓ on request – ✓ ✓ ✓
O-ring

EPDM “D” J22 ✓ on request – ✓ ✓ ✓

FKM “L” J23 ✓ on request – ✓ ✓ ✓
Soft seat
FFKM “C” J20 ✓ on request – ✓ ✓ ✓
SP “T” J49 ✓ – – ✓ – –
Sealing
plate

PCTFE “G” J48 ✓ – – ✓ – –

PTFE “A” J44 ✓ – – ✓ – –
Bellows (Item 15, item70)
select
Balanced bellows J78 ✓ ✓ Type 4414 ✓ ✓ ✓

select
Low pressure bellows J78J63 ✓ – Type 4414 ✓ on request on request

Special Hastelloy J81 select

✓ ✓ Type 4414 ✓ ✓ ✓
materials INCONEL S15
High temperature equipment J88 – – – – ✓ ✓
Elastomer EPDM J79 select
✓ – Type 4414 ✓ – –
bellows NBR J87
Caps and levers (Item 40)
H2 ✓ ✓ ✓ ✓ ✓ ✓
H3 ✓ – – ✓ ✓ ✓
H4 ✓ ✓ ✓ ✓ ✓ ✓
Bolted H1 – ✓ – – – –
H6 – ✓ – – – –

Item – Numbers of the components please refer to standard master bill of materials and sectional drawing.
Options

99/02 LWN 482.01-E

Accessories and Options
Overview

Options
Type 441, 442 DIN 441, 442 XXL 444 DIN 441 FN DIN 455/456 457/458
441, 442 ANSI 444 ANSI 441 FN ANSI
442 FN DIN
Option code 442 FN ANSI
Spring (Pos. 54)
Heat resistant X01 ✓ ✓ ✓ ✓ ✓ ✓
Corrosion resistant 1.4310 X04 ✓ ✓ ✓ ✓ ✓ ✓
INCONEL X-750 X08 on request on request on request on request ✓ ✓
Test gag
H2 (H1) J70 ✓ ✓ ✓ ✓ ✓ ✓
H4 (H6) J69 ✓ ✓ ✓ ✓ ✓ ✓
Bonnet (Item 9)
closed ✓ ✓ ✓ ✓ ✓ ✓
open ✓ ✓ – ✓ ✓ ✓
Heating jacket
✓ – – ✓ ✓ ✓
Lift indicator
Cap/Lifting device H2 (H1), H4 (H6) J39J93 ✓ ✓ ✓ ✓ ✓ ✓
Bonnet J38J93 – – ✓ – – –
Lift stopper
Bush J51 ✓ ✓ ✓ ✓ ✓ ✓
H2 J52
Gag ✓ ✓ ✓ ✓ ✓ ✓
H4 J50
Drain hole
G1/4 J18
✓ ✓ – ✓ ✓ ✓
G1/2 J19
O-ring damper ( Item 40)
H2 J65 ✓ – ✓ ✓ – –
H4 J66 ✓ – ✓ ✓ – –
Bursting disc KUB
✓ – ✓ ✓ ✓ ✓
See Catalog „Best Availability“

Options

LWN 482.01-E 99/03

 Accessories and Options
Caps and levers – Subassembly item 40

Cap H2 Packed lever H4

1

12

2 14 1.5

25 13

25
24 3a

24
1.6
23
23

1.8
1.10
1.7
1.11

1.9

1.4

Plain lever H3 Test gag

Cap H2: J70
Packed lever H4: J69
12

14
93 93.5
6
13
3b
1
22 BLOCKED
23 Remove
after testing

24

10

Test gag The test gag is used for:

- to perform pressure tests in a system without dismantling
The test gag prevents the spindle from lifting and keeps the of the safety valve
safety valve tight while the system pressure exceeds the set - the individual adjustment of safety valves installed
pressure. in the same system

After testing the test gag must be removed because otherwise

Options

the safety valve cannot protect the system against unallowable

overpressure!

99/04 LWN 482.01-E

Accessories and Options
Caps and levers – Subassembly item 40

Materials
Steel Stainless steel

Item Component Cap H2 Plain lever H3 Packed lever H4 Cap H2 Packed lever H4

– 0.7040 0.7040 – 1.4408

1 Lever cover
– Gr. 60-40-18 Gr. 60-40-18 – CF8M
1.0718 – – 1.4404 –
2 Cap
Steel – – 316L –
– – 1.4571 – 1.4571
3a Spacer
– – 316Ti – 316Ti
– 1.4401 – – –
3b Hex screw
– B8M – – –
– 1.4021 1.0718 – 1.4404
4/1.4 Shaft / bolt
– 420 Steel – 316L
– – 1.0531 – 1.4571
1.5 Lifting fork
– – Steel – 316Ti
– 0.7040 1.0036 – 1.4301
6/1.6 Lever
– Gr. 60-40-18 Steel – 304
– – 1.4401 – 1.4301
1.7 Washer
– – 316 – 304
– – A2/Poly – 1.4401
1.8 Nut
– – 2H – 8M
– – Viton® – –
1.9 O-ring
– – Viton® – –
– – – – Graphite
1.9 Bushing
– – – – Graphite
– Carbon steel Carbon steel – –
10/1.10 Retaining clip
– Carbon steel Carbon steel – –
– – – – 1.4104
1.10 Nut
– – – – Chrome steel
– – – – 1.4404
1.10 Packing gland
– – – – 316L
– – Carbon steel – –
1.11 Support ring
– – Carbon steel – –
– 1.0718 1.0718 – 1.4404
12 Spindle cap
– Carbon steel Carbon steel – 316L
– Steel Steel – 1.4401
13 Pin
– Steel Steel – 8M
– 1.4571 1.4571 – 1.4571
14 Retaining clip
– 316Ti 316Ti – 316Ti
– Plastic – – –
22 Plug
– Plastic – – –
Plastic Plastic Plastic Plastic Plastic
23 Seal
Plastic Plastic Plastic Plastic Plastic
1.4541 1.4541 1.4541 1.4541 1.4541
24 Seal wire
321 321 321 321 321
1.4435 – – 1.4435 1.4435
25 Sealing nose
316L – – 316L 316L
1.4401 – 1.4401 1.4401 1.4401
93 Test gag
B8M – B8M B8M B8M
Fiber – Fiber Fiber Fiber
93.5 Washer
Fiber – Fiber Fiber Fiber

Please notice:
Options

– Modifications reserved by LESER.

– LESER can upgrade materials without notice.
– Every part can be replaced by other material acc. to customer specification.

LWN 482.01-E 99/05

 Accessories and Options
Caps and levers bolted – Subassembly item 40

Bolted Cap H1 Bolted lifting device H6

21

2
20

3
14 1.1
24
13
1.5
23

24 12

21 1.6

20

23

Test gag
Bolted cap H1: J70
Bolted lifting device H6: J69

1.8

1.7

BLOCKED
93 Remove after testing 1.10

93.5
1.9

1.4

24

23
Options

Discription of the test gag please refer to page 99/04.

99/06 LWN 482.01-E

Accessories and Options
Caps and levers bolted – Subassembly item 40

Materials
Steel Stainless steel

Item Component Bolted cap H1 Bolted lifting device H6 Bolted cap H1 Bolted lifting device H6

– 0.7040 – 1.4408
1.1 Lever cover
– Gr. 60-40-18 – CF8M
– 1.0718 – 1.4404
1.4 Shaft/bolt
– Steel – 316L
– 1.4408 – 1.4408
1.5 Lifting fork
– CF8M – CF8M
– 1.0036 – 1.4571
1.6 Lever
– Carbon steel – 316Ti
– Steel – 1.4401
1.7 Washer
– Steel – 316
– 1.0501 – 1.4401
1.8 Nut
– 2H – 8M
– Graphite – Graphite
1.9 Bushing
– Graphite – Graphite
– 1.4104 – 1.4404
1.10 Packing gland
– Chrome steel – 316L
0.7040 – 1.4408 –
2 Cap
Gr. 60-40-18 – CF8M –
Graphite / 1.4401 Graphite / 1.4401 1.4571 1.4571
3 Gasket
Graphite / 316L Graphite / 316L 316Ti 316Ti
– 1.0718 – 1.4404
12 Spindle cap
– Carbon steel – 316L
– Steel – 1.4401
13 Pin
– Steel – 8M
– 1.4571 – 1.4571
14 Retaining clip
– 316Ti – 316Ti
1.1181 1.1181 1.4401 1.4401
20 Stud
Steel Steel B8M B8M
1.0501 1.0501 1.4401 1.4401
21 Nut
2H 2H 8M 8M
Plastic Plastic Plastic Plastic
23 Seal
Plastic Plastic Plastic Plastic
1.4541 1.4541 1.4541 1.4541
24 Seal wire
321 321 321 321
1.4401 1.4401 1.4401 1.4401
93 Test gag
B8M B8M B8M B8M
Fiber Fiber Fiber Fiber
93.5 Washer
Fiber Fiber Fiber Fiber

Please notice:

– Modifications reserved by LESER.

– LESER can upgrade materials without notice.
– Every part can be replaced by other material acc. to customer specification.
Options

LWN 482.01-E 99/07

 Accessories and Options
Metal seat – Seat/nozzle item 5 and disc subassembly item 7

The LESER metal seats (disc and nozzle) are lapped to optical „Improved tightness“ Option code J86 is available on request.
flatness to ensure a tight seal. LESER safety relief valves are
supplied with standard leak tightness according to API 527.

Series 441 Series XXL Series 444 Series 458

Series 441 Full Nozzle

1
1 1

2 3 5
1 3
2 2 2
4

Stellited sealing surfaces

The sealing surfaces of stainless steel disc and nozzle can - high pressure applications, due to the high stress of the
be stellited by build-up welding. Stellite is a cobalt-chromium sealing surfaces
based, non-ferrous alloy with increased hardness, corrosion - high temperature applications to avoid a permanent deforma-
resistance and wear resistance up to high temperatures. tion of the sealing surfaces, due to the material properties of
the seat and disc
LESER recommends stellited sealing surfaces for High - applications with abrasive fluids to increase the wear resi-
Performance valves (seat and disc 1.4404 / 316L) in the follow- stance of the sealing surfaces
ing cases:

Series 441 Series XXL Series 458

7.1
7.1 7.1

5
5

Materials for disc and seat/nozzle see page 99/09.

Hardness metal seat

Material Hardness of sealing surfaces

Values from standards or Average value

EN ASME
manufacturers specification LESER stock

EN 10088-3, 1.4122 hardened Hardened stainless steel ≥ 40 HRC LWN 325.01 Harding procedure 42 – 46 HRC
EN 10272, 1.4404 SA 479 316L ≤ 215 HBW EN 10272 Table 7 16 – 19 HRC1)
EN 10272, 1.4404 stellited SA 479 316L stellited ≥ 35 HRC Manufacturers specification 40 HRC

HBW: BRINELL hardness acc. DIN EN ISO 6506-1 / HRC: ROCKWELL hardness acc. DIN EN ISO 6508-1
Options

1) Rockwell hardness values below 20 HRC are not allowed according to DIN EN ISO 6508-1.
Lower, fictitious values were created for better comparison.

99/08 LWN 482.01-E

Accessories and Options
Metal seat – Seat/nozzle item 5 and disc subassembly item 7

Standard and corrosive service

Materials Disc – Subassembly item 7

Item Component Steel Stainless steel
Series 441, 441 Full nozzle
1.4122 hardened 1.4404
1 Disc
Hardened stainless steel 316L
1.4404 1.4404
2 Lifting aid
316L 316L
Series XXL
1.4404, 1.4571 1.4404, 1.4571
1 Disc
316L, 316Ti 316L, 316Ti
1.4581, 1.4571 1.4581, 1.4571
2 Lifting aid
CF10M, 316Ti CF10M, 316Ti
1.4401 1.4401
5 Screw
B8M B8M
1.4401 1.4401
6 Nut
8M 8M
1.4401 1.4401
7 Washer
Stainless steel Stainless steel
Series 444
– 1.4404
1 Disc
– 316L
– 1.4404
2 Lifting aid
– 316L
Securing ring – 1.4571
3
(DN 25/1" only) – 316Ti
– 1.4310
3 Rollpin
– Stainless steel
Series 458
1.4122 hardened 1.4404
1 Disc
Hardened stainless steel 316L
1.4404 1.4404
2 Lifting aid
316L 316L
1.4571 1.4571
3 Securing ring
316Ti 316Ti

Materials Seat / nozzle – Item 5

Item Component Steel Stainless steel
All Series
5 Seat / nozzle refer to respective master bill of materials

Stellited sealing surfaces

Materials Seat / nozzle – Item 5, disc – Item 7

Item Component Option code
Series 441, XXL, 458
1.4404 stellited, 1.4571 stellited
Options

7.1 Disc J25

316L stellited, 316Ti stellited
1.4404 stellited, 1.0305 stellited, 1.4571 stellited
5 Seat / nozzle L61 / L62
316L stellited, carbon steel stellited, 316Ti stellited

LWN 482.01-E 99/09

 Accessories and Options
Soft seal disc – Subassembly item 7

LESER soft seal solutions allow for superior tightness.

Features and Benefits

• two different designs with o-ring or sealing plate (Series 441 • simple replacement of the soft seal reduces maintenance
and 441 Full Nozzle only) for a wide variety application costs
• large selection of soft seal materials to best adapt to the • standard ARP O-ring sizes for easy worldwide procurement
application • one standard durometer per O-ring material for all
• increased service life of sealing surfaces compared to a set pressures to reduce stocking expenses
metal to metal seat

Design of soft seal O-ring disc / Option codes J20 - J23, J30

Series 441 Series XXL Series 458

Series 441 Full Nozzle

ER
LES
5 n t act
se c
o sign
Plea l de
s p ezia om 3
for ser.c
3 a l e s@le 1
s

1 5

4 4

Code letter

Design of soft seal Disc with sealing plate / Option codes J44, J48, J49

Series 441
Series 441 Full Nozzle

Code letter

For temperature limits, medium resistance and option codes please refer to the soft seal selection table, page 99/12.
Materials for soft seal discs see page 99/11.
Options

99/10 LWN 482.01-E

Accessories and Options
Soft seal disc – Subassembly item 7

Materials O-ring disc

Item Component Steel Stainless steel
Series 441, 441 Full nozzle, 458
1.4404 1.4404
1 Disc with lifting aid
316L 316L
1.4404 1.4404
3 Retainer
316L 316L

4 O-ring See soft seal selection table page 99/12 See soft seal selection table page 99/12

1.4401 1.4401
5 Nut
8M 8M

Materials Disc with sealing plate

Item Component Steel Stainless steel
Series 441, 441 Full nozzle
1.4404 1.4404
1 Disc with lifting aid
316L 316L
1.4404 1.4404
3 Retainer
316L 316L

4 Sealing plate See soft seal selection table page 99/12 See soft seal selection table page 99/12

1.4401 1.4401
5 Nut
8M 8M

Options

LWN 482.01-E 99/11

 Accessories and Options
Soft seal

Soft seal selection

Abbrevation Trade name Code- Option Tmin Tmax
Application2)
ASTM 1418 (Designation) letter1) Code [°C] [°F] [°C] [°F]
O-ring
Parafin oil, silicone oil and grease, water and
CR Neoprene® K J21 -40 -40 100 212
waterbased solvents, refrigerants, ozone

Buna-N®
NBR (Nitrile-Butadiene) N J30 -25 -13 100 212 Hydraulic oil, vegetable and animal grease and oil

Buna-EP® Hot water and superheated steam up to 150 °C,

EPDM (Ethylene-Propylene- D J22 -45 -49 150 302 302 °F, some organic and inorganic acids,
Dine) silicone oil and grease, FDA compliant
High temperature service (no superheated steam),
Viton® mineral oil and grease, silicone oil and grease,
FKM (Fluorocarbon) L J23 20 -4 180 356
vegetable and animal grease and oil, ozone, FDA
compliant compound available on request
Nearly all chemicals, standard compound is
Kalrez®
FFKM C J20 0 32 250 482 Kalrez® 6375 with steam resistance, FDA compliant
(Perfluoro)
compound available on request
Sealing plate
High temperature and high pressure applications
VESPEL SP-1® 3)
SP (Polyimide) T J49 -270 -454 300 572 (no steam), for chemical resistance refer to
manufacturers guide

KEL-F® Cryogenic and refrigeration applications, flammable

PCTFE (Polychlorotri- G J48 -270 -454 204 400 media applications, (e.g. gaseous oxygen) up to
fluoroethylene) 50 bar, 725 psig at 60 °C, 140 °F
Teflon®
PTFE (Polytetrafluoro- A J44 -184 -300 150 302 Nearly all chemicals
ethylene)
For other materials please contact your
Other than listed X local representative or sales@leser.com

1) The code letters will be stamped on the disc (Item 1).

2) Pressure and temperature service must be considered in any case.
Chemical resistance information is supplied by the O-ring manufacturer. LESER can not take any warranty.
3) For valve size DN 25, 1" x 2" only.
Options

99/12 LWN 482.01-E

Accessories and Options
Soft seal

Soft seal disc Set pressure and size limits

Pressure range
DIN
Material min. max.
Valve size
[bar] [psig] [bar] [psig]
Series 441. 441 Full nozzle
CR “K” J21
NBR “N” J30
DN 20 – 150
EPDM “D” J22 0.1 1.5 51 740
1" – 6"
FKM “L” J23
FFKM “C” J20
SP “T” J49 10 150 51 740 DN 25 / 1"
PCTFE “G” J48 1 15 51 740 DN 25 – 125 / 1" – 5"
PTFE “A” J44 1 15 10 145 DN 25 – 125 / 1" – 5"
Series 458
– – – – DN 25 / 1", d0 15

4 9 105 225 DN 25 / 1", d0 20

8.6 19 102 225 DN 50 / 2", d0 30

CR “K” J21 3.5 8 102 225 DN 50 / 2", d0 40

NBR “N” J30 4 9 77 170 DN 80 / 3", d0 50

EPDM “D” J22 5 11 77 170 DN 80 / 3", d0 60

FKM “L” J23 4 9 77 170 DN 100 / 4", d0 50

FFKM “C” J20 5 11 77 170 DN 100 / 4", d0 60

2.5 6 60 132 DN 100 / 4", d0 74

2.5 6 51 112 DN 100 / 4", d0 88

2.5 6 40 88 DN 150 / 6", d0 110

Options

LWN 482.01-E 99/13

 Accessories and Options
Balanced bellows – Subassembly item 15

LESER is able to provide a balanced bellows design through AB

the use of stainless steel bellows.
Balanced bellows are generally used for two applications:
– to compensate for back pressure
– to seal off the bonnet from the outlet chamber

FO
Compensation for back pressure pa
The back pressure acts on the reverse side of the disc, creat- FC
ing a force in the closing direction (Fc) of the safety valve. The AS
magnitude of this force depends on the seat area and the level
of the back pressure. The balanced bellows constitute an oppo-
site area with the same area like the seat. The back pressure
acts on, thereby reducing or eliminating the closing force. This
reduction of the force in the closing direction can be viewed as
a compensating force acting in the opening directon (Fo).
A quantitative representation is shown in the table below:
Actual area Back pressure Actual force Direction of force Compensation criteria

Seat area = AS pa FC = pa x AS closing AS = AB

Bellows area = AB pa FO = pa x AB opening FC = FO

Sealing the bonnet from the outlet chamber

LESERs balanced bellows reliably seal the bonnet from the spring from problems associated with the fluid, such as dirt,
outlet chamber; protecting the guide, moving parts and the corrosion, impurities of temperature.

Balanced bellows
Series 441, 441 Full nozzle XXL 458

G 1/4 15.2
Design 15.2
G 1/4
15.2
11
15.5
11
15.3
15.3 15.3

15.1 15.1
15.1

Bonnet spacer * – *
Bellows housing – * *
The bellows housing protects the bellows against turbulences during discharge to avoid bellows vibration and to guarantee a longer life-time.
Control DIN ISO 228-1, G 1/4 * * *
thread ASME B1.20.1 NPT 1/2" ✓ ✓ ✓
A control thread DIN ISO 228-1 size G 1/4 is fitted into the bonnet to monitor the condition of the bellows.
A discharge pipe can be fitted to the G 1/4 control thread to allow safe discharge of aggressive or toxic fluids.
Option code
Standard bellows J68 J68 J68
Open
bonnet Low pressure bellows J68, J63 J68, J63 J68, J63
Other materials than stand. S15 + material designation S15 + material designation S15 + material designation
Standard bellows J78 J78 J78
Low pressure bellows J78, J63 J78, J63 J78, J63
Closed
bonnet Other materials than stand. S15 + material designation S15 + material designation S15 + material designation
Control thread NPT 1/2"
Options

J95 J95 J95

The dimensions and weights of a safety valve with balanced bellows are displayed in the tables “Dimensions and weights” for each type.
The set pressure range as well as the temperature range are displayed in the tables “Pressure temperature ratings” for each type.

99/14 LWN 482.01-E

Accessories and Options
Balanced bellows – Subassembly item 15

Materials Standard bellows

Item Component Series 441, 441 Full nozzle Series XXL Series 458

1.4404 1.4404 1.4404

15.1 Lower adaptor
316L 316L 316L
1.4404 1.4571 1.4404
15.2 Upper adaptor
316L 316Ti 316L
1.4571 1.4571 1.4571
15.3 Bellows
316Ti 316Ti 316Ti
– 1.4571 see item 11
15.5 Housing
– 316Ti see item 11
1.4404 – 1.0460 or 1.4404
11 Bonnet spacer
316L – Carbon steel or 316L
1.4401 1.4401 1.4401
55 Studs
B8M B8M B8M
Graphite / 1.4401 – Graphite / 1.4401
60 Gaskets
Graphite / 316 – Graphite / 316

Hastelloy bellows or special materials are available on request.

Materials Special bellows

Hastelloy® ✓ ✓ ✓

Inconel® ✓ ✓ ✓

Balanced bellows conversion kits

LESER balanced bellows conversion kits are available to convert from a convential design into a balanced bellows design with
little effort. The conversion kits contain all the necessary parts for conversion as well as instructions.

Conversion kits
Item Component Quantity Material

1 1.4404
8 Guide
316L
1 1.4404
11 Bonnet spacer
316L
1 1.4404
12 Spindle
316L
1 1.4571
15 Bellows
316Ti
4, 8, 12 depends on valve size 1.4401
55 Stud
B8M
2, 3 depends on valve size Graphite / 1.4401
60 Gasket
Graphite / 316
Installation instruction 1
– LWN 037.05
Options

For article no. and spare parts please refer to spare part page for each type.

LWN 482.01-E 99/15

 Accessories and Options
High temperature equipment

For fluid temperatures higher than 400 °C / 752 °F high tem- shown is only fitted in Type 457 / 458. For all other Types an
perature equipment is necessary to protect the inner parts and open bonnet and a stainless steel bellows is necessary for fluid
the spring against inadmissible influence of temperature. The temperatures exceeding 400 °C / 752 °F up to max. 450 °C /
maximum inlet temperature is 550 °C / 1022 °F. The equipment 842 °F.

Specification
Series 458

Design
54
55

56

7 11

5 1

15

Option code J88

Operating conditions
Temperature limits [°C] > 400 fluid temperature
[°F] > 752 fluid temperature
max. [°C] 550 inlet temperature
max. [°F] 1022 inlet temperature

Materials High temperature equipment

Item Component

1.7357
1 Body
WC6
1.4404
5 Nozzle
316L
1.4404 stellited
7 Disc
316L stellited
1.0619
9 Bonnet open
WCB
1.4404
11 Cooling spool
316L
1.4571
15 Bellows
316L
1.7102, 1.8159
54 Spring
High temperature alloy steel
1.7709
Options

55 Studs
B16
1.7258
56 Nuts
7M

99/16 LWN 482.01-E

Accessories and Options
Elastomer bellows

Application
Elastomer bellows reliably seal the bonnet from the outlet The range of application for the elastomer bellows is limited
chamber, protecting the guides, moving parts and the spring by:
from problems associated with the media, such as dirt, cor- - chemical resistance of the bellows
rosion or impurities, which can cause the valve the fail. The - fluid temperatur
elastomer bellows is a cost effective alternative to the stainless - set pressure
steel bellows. - back pressure

Elastomer bellows

Design
71

70

72

Bellows design The bellows simple, compact, single wall design allows it to be used in small relieving spaces.
Its one-piece construction also allows to be easily replaced and extends its service life.

Flexibility The bending of the elastomer bellows provides maximum flexibility for
spindle movement and reduces wear.

Bonnet vent A control bore Ø 10 mm / 0,4 inch is designed in the bonnet to vent and to monitor the
tightness of the bellows.
Design height No alteration.

Materials
Valve size DN 20 – 65 DN 80 – 150 DN 20 – 150
1" – 3" 4" 1" – 4"
DN 20 – 50: J87
Option code J79 J79
DN 65 – 150: J87+S70
Item Component

70 EPDM 281 55 EPDM 259 45 NBR 670 optional

70 Elastomer Bellows
70 EPDM 281 55 EPDM 259 45 NBR 670 optional
1.4301 1.4301 1.4301
71 Hose clamp
304 304 304
1.4301 1.4301 1.4301
72 Hose clamp
304 304 304

Operating conditions
Temperature limits [°C] -50 up to +130 -50 up to +130 -25 up to +100
[°F] -58 up to +266 -58 up to +266 -13 up to +212
Set pressure max. [barg] 10
max. [psig] 145
Options

Built-up [barg] up to 3
back pressure
[psig] up to 43,5

LWN 482.01-E 99/17

 Accessories and Options
Disc – Subassembly item 7

Disc with detachable lifting aid

As a variation on the standard disc with an integrally fixed lift- The advantage when servicing the safety valve is that damage
ing aid, a detachable lifting aid for the disc can be supplied if to the sealing surface can be rectified on site by removal and
requested. lapping.

Series 441, 444 Series XXL Series 458

Series 441 Full Nozzle

1
1
1

3 5
2 5

2
6 2

Materials see page 99/19.

Bull race disc

To avoid damages on the sealing surfaces due to frequent or regular maintenance intervals, a bull race disc can be
dismantling, specially on safety valves which have short and / supplied. For Series 458 a bull race disc is standard.

Series 441, 444 Series 458

Series 441 Full nozzle

1
1
3
5
2
2

Availability
Type 441, 442 DIN 441, 442 XXL 444 DIN 441 FN DIN 455/456 457/458
441, 442 ANSI 444 ANSI 441 FN ANSI
442 FN DIN
442 FN ANSI
Disc Option code
Disc with detachable lifting aid J26 * * J26 * *
Bull race disc J24 J24 J24 J24 * *
Options

99/18 LWN 482.01-E

Accessories and Options
Disc – Subassembly item 7

Materials Disc with detachable lifting aid

Item Component Standard service Corrosive service
Series 441, 441 Full nozzle
1.4122 hardened 1.4404
1 Disc
Hardened stainless steel 316L
1.4581 1.4581
2 Lifting aid
CF10M CF10M
1.4310 1.4310
3 Rollpin
Stainless steel Stainless steel
Series XXL
1.4404 1.4404
1 Disc
316L 316L
1.4581 1.4581
2 Lifting aid
CF10M CF10M
1.4401 1.4401
5 Screw
Stainless steel Stainless steel
1.4401 1.4401
6 Nut
Stainless steel Stainless steel
1.4401 1.4401
7 Washer
Stainless steel Stainless steel
Series 458
1.4122 hardened 1.4404
1 Disc
Hardened stainless steel 316L
1.4404 1.4404
2 Lifting aid
316L 316L
1.4571 1.4571
5 Securing ring
316Ti 316Ti

Options

LWN 482.01-E 99/19

 Accessories and Options
Heating jacket

Application and design

Safety valves in systems which need to be protected from If there is no risk of solidification of the media at the outlet a
media that are viscous, sticky, or have the tendency to crystal- safety valve without balanced bellows can be used as well. The
lize out of solution can be fitted with a heating jacket. position of the heating connections is shown in figure 1 to 3.

The heating jacket is constructed with a welded design and

covers the body, allowing heating medias (steam, heat transfer
Specifications of the Heating Jacket
oil, etc.) to pass through the space created. The operating data for the heating jacket are shown on a
separate name plate.
To protect the spindle and the moving parts against sticking
LESER recommends the use of a heating jacket in combination
with the balanced bellows design.
Slip on flanges
Flanged heating connections are
For safety valves with balanced bellows, the bonnet spacer supplied as slip on flanges for better
required to house the bellows is fitted with an additional heating alignment of the flange connection.
jacket. Both heating jackets are joined by a tubing.

DN
G DN

D G A DN A
DN
B B

C C E E

1. Heating jacket for balanced bellows 2. Heating jacket with couplings 3. Heating jacket with slip on flanges
design

Heating jacket
DNI 25 32 40 50 65 80 100 125 150 200 ≥ 250
Valve size inlet 1" 1 1/2" 1 1/2" 2" 2 1/2" 3" 4" 5" 6" 8" ≥ 10"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 74 92 98 125 165 ≥ 200
Materials
Body Series 441 1.4408 1.4408 1.4408 1.4408 1.4408
Series 441 Full nozzle 1.4408 1.4408 1.4408 1.4408 optional optional optional optional optional 1.0619 –
1.0619 1.0619 1.0619 1.0619 1.0619
1.0460 1.0460
Series XXL – – – – – – – – –
1.0425 1.0425
1.4581 1.4581 1.4581 1.4581 1.4581
Series 458 1.4581 1.4581 1.4581 1.4581 optional optional optional optional optional – –
1.0619 1.0619 1.0619 1.0619 1.0619
Heating jacket 1.4541
321
Connections
Option code
Slip on 1.4571, 1.4404 –
H 31 DN 15, PN 25
flange 316Ti, 316L –
DIN – 1.4571, 1.4404
H 32 DN 25, PN 25
– 316Ti, 316L
Slip on
1/2", CL150
1.4404 –
flange K 31
316L –
ANSI B16.5 – 1.4404
K 32 1", CL150
– 316L
Couplings 1.4571
H 29 G 3/8
DIN 2986 316Ti
Options

1.4571
H 30 G 3/4
316Ti
Heating 1.4404
jacket H 33
spacer 316L

99/20 LWN 482.01-E

Accessories and Options
Heating jacket

Metric Units
DNI 25 32 40 50 65 80 100 125 150 200 ≥ 250
Valve size inlet 1" 1 1/2" 11/2" 2" 21/2 " 3" 4" 5" 6" 8" ≥ 10"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 74 92 98 125 165 ≥ 200
Series 441, Series 441 Full nozzle, Series XXL Dimensions
[mm] A 115 130 160 160 200 165 160 170 390 on request on request

B 70 70 75 80 90 80 80 125 125 on request on request

C 95 95 110 110 135 145 145 162 162 on request on request

D 152 170 198 220 255 300 300 370 445 on request on request

E 121 121 121 136 161 176 176 200 200 on request on request

Slip on flange DN 15 15 15 15 15 25 25 25 25 25 25
[inch] Couplings G 3/8 3/8 3/8 3/8 3/8 3/4 3/4 3/4 3/4 3/4 3/4
Operating conditions Operating pressure [bar]
Operating 20 °C 25 25 25 25 15 15 15 15 12 12 on request
temperature 300 °C 18 18 18 18 11 11 11 11 9 9 on request

Series 458 Dimensions

[mm] A 130 – – 170 – on request on request – – – –
B 88 – – 112 – on request on request – – – –
C 96 – – 123 – on request on request – – – –
D 185 – – 251 – on request on request – – – –
E 122 – – 149 – on request on request – – – –
Slip on flange DN 15 – – 15 – on request on request – – – –
[inch] Couplings G 3/8 – – 3/8 – on request on request – – – –
Operating conditions Operating pressure [bar]
Operating 20 °C 25 – – 15 – 15 12 – – – –
temperature 300 °C 18 – – 11 – 11 9 – – – –

US Units
DNI 25 32 40 50 65 80 100 125 150 200 ≥ 250
Valve size inlet 1" 1 1/2" 1 1/2" 2" 2 1/2" 3“ 4" 5" 6" 8" ≥ 10"
Actual Orifice diameter d0 [mm] 23 29 37 46 60 74 92 98 125 165 ≥ 200
Series 441, Series 441 Full nozzle, Series XXL Dimensions
[inch] A 4 1/2 5 1/8 6 5/16 6 5/16 7 7/8 6 1/2 6 5/16 6 11/16 15 3/8 on request on request

B 2 3/4 2 3/4 3 3 1/8 3 1/2 3 1/8 4 1/2 5 5 on request on request

C 3 3/4 3 3/4 4 5/16 4 5/16 5 5/16 5 11/16 6 3/8 6 3/8 6 3/8 on request on request

D 6 6 11/16 7 13/16 8 11/16 10 1/16 11 3/4 13 3/8 14 5/8 17 1/2 on request on request

E 4 3/4 4 3/4 4 3/4 5 3/8 6 3/8 6 15/16 7 7/8 7 7/8 7 7/8 on request on request

Slip on flange DNI 1/2 1/2 1/2 1/2 1/2 1 1 1 1 1 1

[inch] Couplings G 3/8 3/8 3/8 3/8 3/8 3/4 3/4 3/4 3/4 3/4 3/4
Operating conditions Operating pressure [psig]
Operating 68°F 363 363 363 363 217 217 217 217 174 174 on request
temperature 572°F 261 261 261 261 160 160 160 160 131 131 on request

Series 458 Dimensions

[inch] A 130 – – 170 – on request on request – – – –
B 88 – – 112 – on request on request – – – –
C 96 – – 123 – on request on request – – – –
D 185 – – 251 – on request on request – – – –
E 122 – – 149 – on request on request – – – –
Slip on flange DN 1/2 – – 1/2 – on request on request – – – –
[inch] Couplings G 3/8 – – 3/8 – on request on request – – – –
Options

Operating conditions Operating pressure [psig]

Operating 68°F 363 – – 217 – 217 174 – – – –
temperature 572°F 261 – – 160 – 160 131 – – – –

LWN 482.01-E 99/21

 Accessories and Options
O-ring damper – Subassemly item 40

The O-ring damper can be employed to suppress or reduce Flutter: “Abnormal rapid reciprocating motion of the movable
oscillations of moving parts in a safety valve. (Flattern) parts of a pressure relief valve in which the disc does
not contact the seat.” Causes for fluttering are vibra-
tions with small or hardly measurable amplitude, where
Background high frequency vibrations accumulate from external
In every spring loaded safety valve the movable parts disc, influences. The vibrations are usually induced by sepa-
spindle, lower spring plate and the spring form a so called rate units (e.g. motors, pumps) and transmitted via a
spring-mass system. As with all spring-mass systems, these mechanical connection or the medium to the safety
parts can become excited by unfavorable operating conditions valve.
(e.g. inlet pressure drop) or by vibrations transferred from other
equipment. Vibrations occuring at resonance frequency can LESER developed the O-ring damper at LESER‘s certified test
cause the safety valve to undergo rapid, uncontrolled opening labs based on long experience in the operation of safety valves.
and closing, which will cause the valve to function improperly The O-ring damper is able to completely stabilize function or
and not allow it to relieve the certified capacity. reduce oscillations to slow, uncritical movements. Also, the
safety valve will still operate within the required ranges of the
In general two kinds of uncontrolled oscillations exists (defini- applicable codes and standards. Due to its design, the O-ring
tions according to ASME PTC 25-2001, chapter 2.7): damper is able to be used for any type of oscillation.

Chatter: “Abnormal rapid reciprocating motion of the mov- LESER offers the O-ring damper incorporated in the gastight
(Rattern) able parts of a pressure relief valve in which the disc cap H2 or in a modified lifting device H4 with packed lever.
contacts the seat.” Causes for chattering are, among For applications with lubricating fluids, e.g. oil, the balanced
other things, high pressure losses in the inlet piping, bellows design must be selected to protect the O-ring damper
excessive built-up back pressure and operation of the from the fluid.
valve in the partial load range.

Available designs
Cap H2 Packed lever H4

Design 82

22

83

27

15
82
13
22
14
83
1
27

Conventionel design J65 J66

Option
code
Balanced bellows design J65, J78 J66, J78

Temperature range O-ring

Options

-20 °C – +180 °C
-4 °F – +356 °F

99/22 LWN 482.01-E

Accessories and Options
O-ring damper – Subassemly item 40

Availability
Cap H2 and Packed lever H4
Valve size Pressure range
Series 441
DN 25 – DN 50 0.5 – 40 bar
1" – 2" 7.25 – 580 psig
DN 65 0.26 – 40 bar
21/2" 3.77 – 580 psig
DN 80 0.60 – 22.5 bar
3" 8.70 – 326 psig
DN 100 1.17 – 19.2 bar
4" 17 – 278 psig
Series 458
DN 25, d0 20 30 – 90 bar
1", d0 20 435 – 1305 psig
DN 50, d0 40 32 – 67 bar
2", d0 40 464 – 971 psig

LESER has ensured proper performance of the O-ring damper through be performed, which will require a longer lead time; please contact
extensive tests at its certified test labs. If an O-ring damper is required sales@leser.com.
for a set pressure not listed in the table above further testing must

Materials
Item Component Cap H2 Packed lever H4

– 1.4408
1 Lever cover
– CF8M
1.4404 1.4404
2 Cap H2
316L 316L
– 1.4401
13 Parallel pin
– B8M
– 1.4571
14 Securing ring
– 316Ti
– 1.4404
15 Spindle
– 316L
1.4404 1.4404
22 Opposite ring
316L 316L
1.4404 –
27 Bush
316L –
– PFTE 15% glass
27 Nozzle
– PFTE 15% glass
1.4310 1.4310
82 Spring
Stainless steel Stainless steel
FKM FKM
83 O-ring
FKM FKM
Options

LWN 482.01-E 99/23

 Accessories and Options
Lift indicator

The lift indicator is a useful device that can be used in process

94
control to monitor the operating status of a safety valve. To
detect lifting, LESER provides a special lifting device H4 incor-
porating a proximity switch (see drawing right).
The lift indicator will detect a safety valve lift equal to or more
than 1 mm / 0.04 in, which may be the result of overpressure or
of operation of the lifting device.

LESER provides inductive DC proximity switches, type DIN EN

60947-5-6 (NAMUR) using two-wire technology. These intrinsi-
cally safe proximity switches can be used in explosion hazard Packed lever H4 or bolted H6
area zone 0 ( II 1 D Ex iaD 20 T6). Other types of proximity
switch may be used. If a technical specification is supplied
along with the type of connection thread LESER can verify
compatibility.

For technical details of proximity switch refer to manufacturers

homepage: www.pepperl-fuchs.com

For assembly and adjustment refer to LESER works standard

LWN 323.02-E.

Type 444 DN 25 / 1":

Bonnet with adaptor for lift indicator
Availability
Item Component Option code

9 Bonnet with adaptor for lift indicator J38

40 Lifting device H4 with adaptor for proximity switch M18 x 1 [mm] J39

Lift indicator
94 J93
M18 x 1, used type = PEPPERL+FUCHS NJ5-18GK-N

Operating chart
A, closed position B, open position

When the safety valve opens or is lifted

(in both cases at least 1 mm / 0.04 inch),
The lift indicator is positioned in front of the coupling
the lift indicator changes its signal. The signal also
or control sleeve when the safety valve is closed.
changes if the lift indicator accidentally becomes
loosened or unscrewed (fail safe).

Valve lift min.

1 mm / 0.04 inch
Signal

Closed position Open position

High

Low
Options

Valve opens time

99/24 LWN 482.01-E

Accessories and Options
Lift restriction (lift restraining device)

A lift restriction may be needed to reduce the certified discharge valve. If a lift restriction is used the following requirements of
capacity of a safety valve to the required discharge capacity. codes and standards must be considered.
The lift restriction does not interfere with the operation of the

Requirements
Code / standard EN ISO 4126-1, section 5.1.3 ASME Code case 1945-4 AD 2000-Merkblatt A2, section 10.3

≥ 30% full rated lift ≥ 30% full rated lift

Lift not less than 1.0 mm / 1/16 inch
not less than 1.0 mm / 1/16 inch not less than 0.08 inch / 2.0 mm
– – αw [S/G] ≥ 0.08
Coefficient of discharge
– – αw [L] ≥ 0.05
- Capacity replaced with
Marking of reduced Marking of reduced
Name plate marking “Restricted capacity”
coefficient of discharge coefficient of discharge
- Restricted lift =_____ inch / mm

The restriction of valve capacity shall be permitted only by the use of a lift restraining device, which shall
Design according to ASME
limit valve lift and shall not otherwise interfere with flow throughout of the valve. The lift restricting device
code case 1945-4
shall be designed so that the adjustable feature can be mechanically locked and have access sealed.

Determinating the restricted lift

Determining the restricted lift can be done by using: - LESER sizing program “VALVESTAR®” in reference to the
- the “Diagram for evaluation of ratio of lift/flow diameter (h/d0) - LESER sizing web page www.valvestar.com
coefficient of discharge”. An explanation on how to use this
diagram may be found on page 00/08.

Lift restrictions
Lift restriction by bush Lift restriction by gag

93
Design
96

22

Cap H2 or H1: J52

Option code J51
Packed lever H4 or H6: J50
Availability
Series 441 ✓ ✓
Series 444 ✓ ✓
Series XXL ✓ ✓
Series 441 Full nozzle ✓ ✓
Series 458 ✓ ✓
Materials
Item Component

1.4404 –
22 Bush
316L –
– 1.4401
Options

93 Stud
– B8M
– 1.4401
96 Hex nut
– 8M

LWN 482.01-E 99/25