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Packing Selection Guidelines for

Fisherr Sliding-Stem Valves

This bulletin provides information and insight to help

you select Fisher packing systems properly. The

following application guidelines have been developed

to aid in the packing selection process. It is important

to note that these guidelines were developed based on

the results of numerous tests on various packing

systems conducted in the Emerson Process

Managementt laboratory. Exceeding these guidelines

might result in reduced service life.

Thetraditionalvalveselection process includes

selecting a valve design based on pressure and

temperature capabilities, flow characteristics, material

compatibility, and other factors. One such major factor

is packing selection, which has gained significant

attention over the years due to stringent

environmental and safety concerns.

Proper packing selection is being driven by USA Clean

Air Act Amendments and subsequent EPA

(Environmental Protection Agency) regulations, as well

as our customers' increasing concern for improved

packing performance (less maintenance and longer

life). Seal performance continues to be a focus item.

In the past, packing selection was primarily based on

process temperature; that is, PTFE was selected for

temperatures below 232_C(450_F) and graphite was

selected for temperatures above 232_C(450_F).

Considerations now include the effect of packing

friction on process control, hysteresis, seal quality, and

cycle life. Given the variety of process applications and

installation conditions, these variables are difficult to

quantify. A relative packing performance comparison

canbemadethatprovidesan engineered approach to

the packing selection process.

Clarification of trade names is required for proper

understanding of the tables shown in this bulletin.

From an Emerson Process Management engineering

perspective, ENVIRO-SEAL packing (figure 1) is defined

as an advanced packing system using a “compact”,

Figure 1. Fisher easy-e™ Valve Bonnet with

ENVIRO-SEAL™ Packing

VALVE

BONNET

BELLEVILLE

SPRINGS

VALVE

STEM

PACKING

FLANGE

PACKING

FOLLOWER

W5814-1*

live-load spring design. From a user perspective,

ENVIRO-SEAL packing is most typically thought of as an

emission-reducing packing system. The HIGH- SEAL

packing system is used in those applications having

extreme pressures and temperatures. HIGH-SEAL

packing uses two “large” live-load springs.

This bulletin will help extend your thinking of

ENVIRO-SEAL packing as being suitable not only for

those applications where the control of fugitive

emissionsisarequirement, but also for

nonenvironmental applications involving higher

temperatures and pressures. The use of ENVIRO-SEAL

packing in nonenvironmental applications offers the

benefit of lower ongoing maintenance costs.

Sliding-Stem Packing Selection

D101986X012

Product Bulletin

59.1:062

December 2012

1 2 3 4 5 6 7 8

Summary of Contents

Page 1 - Fisherr Sliding-Stem Valves

www.Fisher.comPacking Selection Guidelines forFisherr Sliding-Stem ValvesThis bulletin provides information and insight to helpyou select Fisher packi

Page 2 - Product Bulletin

Sliding-Stem Packing SelectionD101986X012Product Bulletin59.1:062December 20122Table 1. Fisher Packing Selection Guidelines for Sliding-Stem ValvesPac

Page 3

Sliding-Stem Packing SelectionD101986X012Product Bulletin59.1:062December 20123Figure 3. Applications Guidelines Chart for Nonenvironmental ServiceENV

Page 4

Sliding-Stem Packing SelectionD101986X012Product Bulletin59.1:062December 20124Single PTFE V-Ring PackingThesinglePTFEV-ring arrangement uses a coil s

Page 5

Sliding-Stem Packing SelectionD101986X012Product Bulletin59.1:062December 20125Figure 4. Typical Fisher P acking ExamplesNote: Leak-off tapping and pi

Page 6 - Services

Sliding-Stem Packing SelectionD101986X012Product Bulletin59.1:062December 20126ENVIRO-SEAL Graphite ULFENVIRO-SEAL graphite ULF packing is designedpri

Page 7

Sliding-Stem Packing SelectionD101986X012Product Bulletin59.1:062December 20127Figure 5. Typical Fisher P acking ExamplesNote: Leak-off tapping and pi

Page 8 - Conclusion

Sliding-Stem Packing SelectionD101986X012Product Bulletin59.1:062December 20128ConclusionIt is important to recognize that many parametersaffect seal