T 8000-6 EN

Packings for Globe Valves

Packing forms and their application ranges

Application
A packing is a dynamic sealing system that seals the moving plug stem to prevent the process medium escaping from the valve
into the atmosphere. The packing must seal the moving plug stem, yet without impairing the valve's performance in any way.

SAMSON AKTIENGESELLSCHAFT · Weismüllerstraße 3 · 60314 Frankfurt am Main, Germany Edition March 2023
Phone: +49 69 4009-0 · Fax: +49 69 4009-1507 · samson@samsongroup.com · www.samsongroup.com
We attach great importance to occupational health and safety – Pressure and temperature resistance
as well as environmental protection in the same way our cus- – Wear resistance
tomers do. Consequently, we offer solutions to meet the in-
– Low friction
creasingly stricter emissions requirements.
– High resistance to corrosive media
Environmental requirements
– Elastic and easily deformable
Particularly strict requirements may apply to the fugitive emis-
sions of a valve depending on the process medium and the Installation of the packing
environmental protection as well as occupational health and The packing is either fixed in place in the valve body by a
safety regulations in place. There are three factors that play a threaded bushing (central threaded fastening, see Fig. 1,
major role in a valve's compliance to environmental require- Fig. 2 and Fig. 5) or using a packing gland and a threadless
ments: bushing (see Fig. 3 and Fig. 4). There are four basic packing
– External leakage (fugitive emissions) designs:

– Seat leakage – Adjustable, one central threaded fastening (see Fig. 5)

– Noise emissions – Spring-loaded, one central threaded fastening (see Fig. 2)

External leakage occurs when the process medium in a control – Adjustable packing gland (see Fig. 3)
valve (e.g. with pneumatic actuator) leaks to the atmosphere – Packing gland loaded by external springs (see Fig. 4)
over the plug stem guide, body gasket or flanged joint. Seat The sealing elements of the adjustable packing are com-
leakage primarily concerns the internal leakage between the pressed between the valve body and plug stem by applying a
seat and plug as well as the joint between the seat and body specified tightening torque. If the packing leaks, the threaded
(see Fig. 1). External leakage from the valve is termed "fugi- bushing or packing gland can be repeatedly tightened further
tive emissions". by the specified tightening torque until the sealing elements
must be replaced.
Live-loaded packings are loaded by internal or external
springs. A pre-loaded spring maintains a constant load on the
sealing elements, which is automatically adjusted, even as the
sealing elements wear down over time until they must be re-
placed.
Live-loaded packings with a tightening option are loaded by
internal springs. After the pre-loaded spring cannot be
compressed any further and the packing starts to leak before
the next routine maintenance is scheduled, the packing can be
External leakage: adjusted one more time by tightening the threaded bushing or
• Plug stem guide packing gland (depending on the design) to curb leakage
(packing/bellows seal)
until the packing can be replaced at the next planned
maintenance.
• Body gasket
• Flanged joint Composition and materials
Packings are available in various varieties and contain several
Internal leakage: rings, one or more bushings and washers. They may also in-
• Between plug and seat clude a spring to load the packing. The combination of parts
• Between seat and body and their material depends on the valve application as well as
pressure, temperature and medium resistance properties etc.
Fig. 1: External and internal leakage in a control valve
There are different types of packing rings, which can be made
Measures to minimize external leakage are divided into two of various materials. Typical packing ring types include
categories: static and dynamic seals. Body gaskets and smooth, V-shaped and braided rings that can be made of
flanged joints belong to the static seal category. Dynamic graphite, PTFE or modified PTFE material.
seals include packings, bellows and diaphragm seals. A stainless steel spring made of 1.4310 (standard), 2.4360
The packing must seal the moving plug stem to ensure the pro- (Monel® 400) or 2.4610 (Hastelloy® C4) is used for the
cess medium inside the valve cannot escape to the atmo- live-loaded packing.
sphere, yet without impairing the valve's performance.

Packing requirements
Packings are contact seals which seal the opening between a
moving and a stationary component. Due to the large area of
contact between the packing and the plug stem as well as the
high compression required to control leakage, the friction gen-
erated by the packing is relatively high when compared to
mechanical seals. Nevertheless, packings are still commonly
used to seal valves when they have the following properties:

2 T 8000-6 EN
Design and principle of operation
An installed packing seals the space between the valve body
and plug stem after the threaded bushing or packing gland is
tightened. This creates an axial force that is applied to the
packing rings. As a result, the rings expand in the radial di-
rection and are pressed against the plug stem. The compres-
sive force applied to the packing seals off any potential paths
of leakage.
Principle based on a live-loaded V-ring packing (see Fig. 7):
The guide bushing (9) is pressed fit at the bottom of the valve
bonnet and surrounds the plug stem. The packing spring (3) is
installed on top of it. The packing rings (1a) are arranged in a
certain sequence above the spring in the packing chamber.
The compressive force is created by tightening the threaded
Fig. 3: Adjustable packing gland (e.g. used in Type 3595 Valve)
bushing (4) or packing gland on the valve bonnet. As a result,
the packing rings (1b) are squeezed together. The V-rings are
pushed into one another and spread out. This creates a tight
seal in the space between the plug stem and valve bonnet. The
same principle applies to other ring-type seals as well.
Excessive leakage can occur if the packing is installed
incorrectly (e.g. uneven, insufficient or excessively high
tightening torque) and/or the wrong packing materials are
used. Over-tightening increases the friction between the
packing and plug stem, which may lead to premature wear
and unwanted jerky plug stem movement. It can also increase
the actuator force required to position the valve.
Unlike the adjustable packing, a spring-loaded packing
cannot be overtightened if the instructions are followed. The
central threaded bushing is tightened as far as it will go.
When using a packing gland, a visual indication is given on
Fig. 4: Live-loaded packing with packing gland (loaded by exter-
the correct tightening position. The spring ensures that an nal springs) with tightening option
even and relatively optimal compressive force is applied to the
packing.
The advantage of an adjustable packing is that it does not
have any springs, making it free of cavities.

Fig. 5: Adjustable packing with threaded bushing (without spring)

Fig. 2: Live-loaded packing with threaded bushing (loaded by in-

ternal springs)

T 8000-6 EN 3
Standards and regulations Table 1: Tightness classes according Tightness class
It is impossible to achieve 100 % tightness in a control valve to ISO 15848-1 for helium as test
AH BH CH
due to the laws of physics and chemistry (i.e. since atoms of a medium
substance diffuse through a solid and/or as a result of dy-
Measured leakage
namic forces created by the moving plug stem). Consequently,
rate (mass flow Stem diameter ≤10–5 ≤10–4 ≤10–2
regulations and standards define the tightness of a packing rate) (information only)
based on permissible leakage limits depending on the process
medium.
The endurance class is used to determine the classification ac-
Such regulations include the German TA Luft (German techni- cording to the number of mechanical cycles. A differentiation
cal instructions on air quality control). This regulation serves to is made between isolating valves and control valves. Isolating
protect the general public from the harmful effects of air pollu- valves are classified according to CO endurance classes and
tion on the environment and to provide precautions against control valves according to CC endurance classes. These en-
harmful effects of air pollution in order to attain a high level of durance classes are subdivided into three stages depending
protection for the environment altogether. on the minimum number of mechanical cycles. A certain se-
The TA Luft regulation requires that sliding-stem valves are quence of cycles is performed for each endurance class. The
fitted with a high-performance bellows seal with backup endurance classes for control valves are listed below as an ex-
packing or use an equivalent gasket sealing system. In the TA ample:
Luft regulation dated 24 July 2002, a gasket sealing system – CC1: 20,000 mechanical cycles (10,000 cycles at room
can be regarded to be equivalent if the temperature-specific temperature and 10,000 cycles at test temperature in to-
leakage rates are met in the verification procedure stipulated tal)
in VDI 2440:2000-11. Compliance is given when the
– CC2: 60,000 mechanical cycles (CC1 + an additional
construction of the sealing system is expected to continually
40,000 cycles consisting of 20,000 cycles at room tem-
fulfill its intended function under the operating conditions and
perature followed by 20,000 cycles at test temperature)
the following specific leakage rates are met:
– CC3: 100,000 mechanical cycles (CC2 + an additional
Temperature <250 °C ≥250 °C
40,000 cycles consisting of 20,000 cycles at room tem-
Specific leakage rate 10–4 10–2 perature followed by 20,000 cycles at test temperature)
If the leakage measured exceeds the values in Table 1 during
The latest edition of the TA Luft regulation came into force on typetesting, it is permissible to mechanically adjust (i.e. tight-
23 June 2021. A transitional period for compliance to the en) the packing once for each qualification stage performed
new requirements ends on 2025-01-01. The latest edition of (according to the endurance class). For example, a maximum
the TA Luft regulation refers to the internationally applicable of three adjustments is permissible for CC3.
ISO 15848-1 concerning equivalent gasket sealing systems.
The tightness test is always performed for a specific tempera-
This standard deals with the measurement, test and
ture and pressure. Fixed temperature classes are defined in
qualification procedures for fugitive emissions in industrial
ISO 15848-1. However, the standard permits a test tempera-
valves. It prescribes specific test procedures and test media.
ture that deviates from the temperature class, which is speci-
Packings are classified according to categories of tightness,
fied in brackets after the temperature class in the performance
temperature and endurance. The number of mechanical cycles
class.
(full strokes) is also classified since it is a relevant factor for
packings.
The objective of DIN EN ISO 15848-1 is to enable a classifi- Fig. 7 to Fig. 11 show various packings.
cation of the performance of different valve designs to reduce
fugitive emissions. It defines the type test for evaluation and
qualification of valves where fugitive emissions standards are
specified.
Testing can only be performed on fully assembled valves. Heli-
um gas (H) or methane (M) of 97 % minimum purity is pre-
scribed as the test medium. After testing, the packing is as-
signed to a performance class (see Fig. 6).

ISO FE BH-CC3-SSA 0-t 200 °C (220 °C)-PN 50/Class 300-ISO 15848-1

Tightness class B
with helium (test fluid) Temperature class Pressure rating
Number of adjustments
Endurance class of the stem seal

Fig. 6: Typical performance class marking for Form LoE packing installed in a Series 240 Valve

4 T 8000-6 EN
Legend for Fig. 7 to Fig. 11
4
1 Packing (entire) 5 Spacer
1a V-ring packing 6 O-ring 8
1b Seals with square/ 7 Seal
rectangular cross-section 8 Spacer
2 Washers 7
9 Guide bushing (PSA
3 Spring version: wiper ring)
1a
4 Threaded bushing
1

4 3

5
1a
9

3
Fig. 9: ADSEAL packing · DN 65 to 80/NPS 2½ to 3

5
6

1a
1
2

Fig. 7: Standard packing · DN 65 to 80/NPS 2½ to 3

3

4 9

Fig. 10: PSA packing · DN 15 to 50/NPS ½ to 2

1a 4
6

1
1b
1a
1
2

2 3

5 5

9
9

Fig. 8: Form A packing · DN 65 to 80/NPS 2½ to 3 Fig. 11: Form LT packing · DN 65 to 80/NPS 2½ to 3

T 8000-6 EN 5
Table 2: Part 1: Packing forms

• = Standard version o = Optional version — = Not with this packing

Form Standard Standard NACE LoE (low emissions) LoE NACE

Live-loaded (spring-loaded) • • • •
Once — — — —
Adjustable
Style Several times o o o o
With packing gland — — — —
With threaded bushing • • • •

V-rings • • • •

Square
Seals — — — —
cross-section

Smooth • • • •
Design Braided — — — —
One • • • •
Bushing(s)
Multiple o o o o
Washer(s) • • • •
Spring • • • •
Single • • • •
Packing
Double o 5) o 5) o 5) o 5)
PTFE-carbon PTFE-carbon PTFE-carbon PTFE-carbon
Seals
(Pure) PTFE (Pure) PTFE (Pure) PTFE (Pure) PTFE
• 1.4301
o 1.4360
Bushing(s) and washers • 2.4610 • 1.4404 • 2.4610
Materials 1) o 1.4404
o 2.4610
• 1.4310
Spring o 2.4360 • 2.4610 • 1.4310 • 2.4610
o 2.4610
Lubricant Yes Yes Yes Yes
Suitability for
pH range 0…14 0…14 0…14 0…14
process medium
–10 to +220 °C 2)
–10 to +220 °C 2)
–50 to +220 °C 6)
–50 to +220 °C 6)
Process medium
Temperature 14 to 428 °F 2) 14 to 428 °F 2) –58 to +428 °F 6) –58 to +428 °F 6)
range –25 to +120 °C –25 to +120 °C –50 to +120 °C –50 to +120 °C
Ambient
–13 to +248 °F –13 to +248 °F –58 to +248 °F –58 to +248 °F
Service life (mechanical cycles) >500,000 >500,000 >500,000 >500,000
DIN EN ISO 15848-1:2017 7) 9) — — • •
Certification
FCI 91-1 (ANSI) — — — —
TA Luft 2002 (VDI 2440) • • • •
Requirements
TA Luft 2021 8) 9) — — • •
(met)
NE 167 8) — — • •

Other certification (e.g. in the food and beverage

— — — —
as well as pharmaceutical industries)

Series 240, 250, 290 240, 250, 290

Suitable for valves
Type 3591, 3510 3591, 3510 3241, 3244 3241, 3244
– For valve sizes DN 15 to – For valve sizes DN 15 to
– High level of sealing 300 300
performance with low – No maintenance – No maintenance
High level of sealing
maintenance require- – Particularly suitable for – Particularly suitable for
Applications/suitability/special features performance with low
ments valves that must have an valves that must have an
maintenance requirements
– Suitable for sour gas effective sealing perfor- effective sealing perfor-
and sour water mance over the entire mance over the entire
temperature range. temperature range.

6 T 8000-6 EN
 A B D H HT Form
— — • — — Live-loaded (spring-loaded)
— — — — • Once
Adjustable
• • o • — Several times Style
— — — — — With packing gland
• • • • • With threaded bushing
• Up to DN 150/
• • — — V-rings
NPS 6
• Up to DN 150/
NPS 6 Square
• — • — Seals
• DN 200/NPS 8 cross-section
and larger
• • • • • Smooth
• • — — • Braided Design
• — • — • One
Bushing(s)
o • o • o Multiple
• • • • • Washer(s)
— — • — — Spring
• • • • • Single
Packing
o 5) o 5) o 5) o 5) Double
PTFE-carbon (Pure) PTFE
(Pure) PTFE (Pure) graphite (Pure) graphite 4) Seals
PTFE-silk PTFE with silk cord
• 1.4301
o 1.4360
• 1.4404 1.4404 Carbon (Pure) graphite 4) Bushing(s) and washers
o 1.4404 Materials 1)
o 2.4610
• 1.4310
— — o 2.4360 — — Spring
o 2.4610
Yes Yes Yes No No Lubricant
Suitability for
0…14 0…14 0…14 0…14 0…14 pH range
process medium
–10 to +220 °C 2)
–10 to +220 °C 2)
–10 to +220 °C 2)
≤350 °C 2)
≤400 °C 2)
Process medium
14 to 428 °F 2) 14 to 428 °F 2) 14 to 428 °F 2) ≤662 °F 2) ≤752 °F 2) Temperature
–25 to +120 °C –25 to +120 °C –29 to +120 °C –50 to +120 °C –50 to +120 °C range
Ambient
–13 to +248 °F –13 to +248 °F –20 to +248 °F –58 to +248 °F –58 to +248 °F
>500,000 >500,000 >500,000 >200,000 >500,000 Service life (mechanical cycles)
— — o 3) — — DIN EN ISO 15848-1:2017 7) 9)
Certification
— — — — — FCI 91-1 (ANSI)
— — — • TA Luft 2002 (VDI 2440)
Requirements
— — — — TA Luft 2021 8) 9)
(met)
— — — — NE 167 8)
o FDA
Other certification (e.g. in the food and beverage
— — o Regulation (EC)
as well as pharmaceutical industries)
No. 1935/2004
240, 250 240, 250 240, 250 240, 250 240, 250 Series
Suitable for valves
Type
– High level of seal-
Cavity-free packing – Suitable for
ing performance
suitable for process high-temperature
Cavity-free packing with low mainte- Suitable for
media that crystal- range (e.g. for su-
suitable for process nance require- high-temperature
lize or polymerize perheated steam) Applications/suitability/special features
media that crystal- ments range (e.g. for su-
and for which discol- – To fulfill graphite
lize or polymerize – For process media perheated steam)
oration is not permit- purity requirements
that are not permit-
ted ≥98 %
ted to discolor

1) Materials that are interdependent as well as being dependent on other fac- 5) Depending on the valve series
tors, such as valve body material, temperature ranges, medium properties etc. 6) Depending on the valve, the use of an insulating section is prescribed for low
2) Medium temperature at the valve inlet (applies to versions without insulating temperatures down to –50 °C (see the data sheet of the corresponding valve).
section and/or bellows seal) 7) Tightness class, test medium, endurance class, temperature class and pressure
3) Manufacturer's Declaration for stem seal exists rating on request
4) Braided end rings made of pure expanded graphite yarn with edges rein- 8) Pressure rating and temperature class on request
forced with carbon fibre, highly compressed washers and specially impreg- 9) Certification for Type 3510 Micro-flow Valve on request
nated adapter rings made of high-density, expanded pure graphite

T 8000-6 EN 7
Table 3: Part 2: Packing forms

• = Standard version o = Optional version — = Not with this packing

Form LT PG PSA W ADSEAL

Live-loaded (spring-loaded) • • • — •
Once — — — — •
Adjustable
Style Several times o • o • —
With packing gland — — — — —
With threaded bushing • • • • •
• Up to DN 150/
•
NPS 6
Additional O-ring
Additional O-ring
acting as a seal be-
V-rings acting as a seal be- • — •
tween threaded
tween threaded
bushing and valve
bushing and valve
Seals bonnet
bonnet
Square
— • • • •
cross-section
Design Smooth • • • • •
Braided — — — • o
One • • • • •
Bushing(s)
Multiple o o o o o
Washer(s) • • • o •
Spring • • • — •
Single • • • • •
Packing
Double o 5) o 5) o 5) o 5) o 5)
PTFE-carbon PTFE-carbon
(Pure) PTFE Synthetic fiber PTFE-carbon
Seals (Pure) PTFE (Pure) PTFE
PTFE-carbon Carbon PTFE with silk cord
Graphite Graphite
Materials 1)
Bushing(s) and washers 1.4404
Spring 1.4310
Lubricant Yes Yes Yes Yes Yes
Suitability for
pH range 0…14 0…14 0…14 0…14 0…14
process medium
–10 to +220 °C 2) –10 to +220 °C 2) –10 to +150 °C –10 to +220 °C 2) –10 to +220 °C 2)
Process medium
Temperature 14 to 428 °F 2) 14 to 428 °F 2) 14 to 302 °F 14 to 428 °F 2) 14 to 428 °F 2)
range –50 to +120 °C –25 to +120 °C –10 to +120 °C –10 to +120 °C –10 to +120 °C
Ambient
–58 to +248 °F –13 to +248 °F 14 to 248 °F 14 to 248 °F 14 to 248 °F
Service life (mechanical cycles) >500,000 >200,000 >200,000 >500,000
DIN EN ISO 15848-1:2017 7) 9)
• — — — —
Certification
FCI 91-1 (ANSI) — — — — —
TA Luft 2002 (VDI 2440) o — — — —
Requirements
TA Luft 2021 8) 9) • — — — —
(met)
NE 167 8) — — — — —
Other certification (e.g. in the food and beverage
as well as pharmaceutical industries)
Series 250, 290 240, 250 240, 250 240, 250 240, 250
Suitable for valves
Type 3591, 3510
– Cavity-free pack-
ing for fresh and
service water – High level of
– High level of seal- – Carbon bushings sealing
ing performance at Special applica- serve as wipers performance with
PSA (Pressure Swing
Applications/suitability/special features low temperatures tion-specific version – Especially suitable low maintenance
Adsorption) plants
– Low maintenance for HyCO plants for hard water and requirements
required any process media – With additional
that may cause tightening option
deposits to form on
the plug stem
1) Materials that are interdependent as well as being dependent on other fac- 5) Depending on the valve series
tors, such as valve body material, temperature ranges, medium properties etc. 6) Depending on the valve, the use of an insulating section is prescribed for low
2) Medium temperature at the valve inlet (applies to versions without insulating temperatures down to –50 °C (see the data sheet of the corresponding valve).
section and/or bellows seal) 7) Tightness class, test medium, endurance class, temperature class and pressure
3) Manufacturer's Declaration for stem seal exists rating on request
2023-04-19 · English

4) Braided end rings made of pure expanded graphite yarn with edges rein- 8) Pressure rating and temperature class on request
forced with carbon fibre, highly compressed washers and specially impreg- 9) Certification for Type 3510 Micro-flow Valve on request
nated adapter rings made of high-density, expanded pure graphite

Specifications subject to change without notice T 8000-6 EN