API

Flanged Safety Relief Valves

Series 526

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The-Safety-Valve.com

1
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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 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

2
General

General Information

The API product group represents

3 Full range of spring loaded safety valves acc. to API 526

3 State-of-the-art design from the safety valve specialist
3 Competitive solutions for the API market

API safety valves from LESER

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full design lift.
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and service specialists.
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worldwide which ensures the worldwide applicability e.g.:

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Equipment Directive (PED) 97 / 23 / EC and EN ISO 4126-1
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National Board certified capacities
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requirements of particular provinces
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Section VIII Division 1 and AD 2000-Merkblatt A2
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Union (EAC - Eurasian Conformity)

Furthermore, all LESER API 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

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4
 Type 526
Type 526
Flanged Safety Relief Valves
– spring loaded

Contents Page
Materials
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Article numbers
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Type 526X SAFUREX 14

Dimensions
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Weights
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Orifice D – T
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Available options 78
API Alloy Concept 80
Sour gas service (NACE) 81
Flange drillings 82
Outlet flange rating class 300 84
Flange facings 87
LESER Original Spare Parts Kits 88
Approvals 89

Capacities
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Determination of coefficient of discharge Kdr / w 96

Type 526
Packed lever H4
Closed bonnet
Conventional design

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 Type 526
Conventional design
Type 526

40 Cap H2

19 Lock nut

18 Adjusting screw

69 Needle bearing

16 Spring plate

54 Spring

12 Spindle

9 Bonnet

14 Split ring

17 Spring plate

55 Stud

56 Nut

8 Guide
Plug 64

60 Gasket

22 Lift restriction

57 Ball

66 Screw

61 Ball

73 Lock screw

7 Disc

6 Adjusting ring

1 Body

5 Nozzle

8
Type 526
Conventional design
Materials

Type 526
Standard Service Type 5262 Corrosive Service Type 5264 Type 5267 Type 5263
Item Component
Trim: Standard Trim: Standard Trim: Standard Trim: Standard

1.0619 1.4408 1.7357

1 Body
6$:&% SA 351 CF8M 6$:& SA 352 LCB
1.4408 1.4408 1.4408 stellited 1.4408
5 Nozzle1)
CF8M CF8M CF8M stellited CF8M
1.4408 1.4408 1.4408 1.4408
6 Adjusting ring
CF8M CF8M CF8M CF8M
1.4122 1.4404 stellited 1.4122 1.4122
7 Disc
Hardened stainless steel 316L stellited Hardened stainless steel Hardened stainless steel
1.0501 1.4404 1.4404 1.0501
Guide
Steel 316L 316L Steel
8
1.4104 tenifer – – 1.4104 tenifer
with bushing
Chrome steel tenifer – – Chrome steel tenifer
1.0619 1.44082) 1.7357
6$:&% SA 351 CF8M 6$:& SA 352 LCB
9 Bonnet
1.03054) 1.4571 / 1.44043) 1.03054) 1.03054)
Steel SA 479 316Ti / 316L Steel Steel
1.4021 1.4404 1.4021 1.4021
12 Spindle
420 316L 420 420
1.4104 1.4404 1.4104 1.4104
14 Split ring
Chrome steel 316L Chrome steel Chrome steel
1.07183) 1.4404 1.07185) 1.07185)
16 / 17 Spring plate
Steel 316L Steel Steel
1.4104 1.4404 tenifer 1.4104 1.4104
Adjusting screw
Chrome steel 316L tenifer Chrome steel Chrome steel
18
37)(JODVV 37)(JODVV 37)(JODVV 37)(JODVV
with bushing
37)(JODVV 37)(JODVV 37)(JODVV 37)(JODVV
1.0718 1.4404 1.0718 1.0718
19 Lock nut
Steel 316L Steel Steel
1.4404 1.4404 1.4404 1.4404
22 Lift restriction
316L 316L 316L 316L
1.0460 / 0.7040 1.4404 1.0460 / 0.7040 1.0460 / 0.7040
40 Cap H2
SA 105 / Gr. 60-40-18 316L SA 105 / Gr. 60-40-18 SA 105 / Gr. 60-40-18
1.7102, 1.8159 1.4310 1.7102, 1.8159 1.7102, 1.8159
54 Spring
High temp. alloy steel Stainless steel High temp. alloy steel High temp. alloy 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
1.4401 1.4401 1.4401 1.4401
57 Ball
316 316 316 316
Graphite / 1.4401 Graphite / 1.4401 Graphite / 1.4401 Graphite / 1.4401
60 Gasket
Graphite / 316 Graphite / 316 Graphite / 316 Graphite / 316
1.3541 1.4401 1.3541 1.3541
61 Ball
Hardened stainless steel 316 Hardened stainless steel Hardened stainless steel
Steel 1.4401 Steel Steel
64 Plug
Steel B8M Steel Steel
1.4401 1.4401 1.4401 1.4401
66 Screw
B8M B8M B8M B8M
1.4404 1.4404 1.4404 1.4404
69 Needle bearing
316L 316 L 316L 316L
1.4404 1.4404 1.4404 1.4404
73 Lock screw
316L 316L 316L 316L
1)
Stellited sealing surfaces please refer to page 10. LESER reserves also to use the nozzle material 1.4404 / 316L. 2)9DOYHVL]HVXSWR3)9DOYHVL]HVŰ
4)
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Please notice: Special materials:
- Modifications reserved by LESER. See API Alloy Concept page 80.
- 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.
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