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Sliding-Stem Packing Selection

Sliding-Stem Packing Selection
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Product Bulletin Sliding-Stem Packing Selection Packing Selection Guidelines for Fisher™ 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 Emersont laboratory. Exceeding these guidelines might result in reduced service life. The traditional valve selection 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 can be made that provides an 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 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 PACKING FLANGE VALVE STEM BELLEVILLE SPRINGS PACKING FOLLOWER VALVE BONNET 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 emissions is a requirement, 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 mainten

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Product Bulletin Sliding-Stem Packing Selection Table 1. Fisher Packing Selection Guidelines for Sliding-Stem Valves Maximum Pressure and Temperature Limits for 100 PPM Service(1) Packing System Application Guideline for Nonenvironmental Service(1) Seal Performance Index Service Life Index Packing Friction Very long Very long Very long Single PTFE V-Ring Double PTFE V-Ring ENVIRO-SEAL PTFE ENVIRO-SEAL Duplex KALREZr with Vespelr CR-6100 (KVSP 500)(3) Very long Very long Very long Very high HIGH-SEAL Graphite ULF Graphite Composite / HIGH-SEAL Graphite Braided Graphite Filament Very long 1....

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Product Bulletin Sliding-Stem Packing Selection Figure 3. Applications Guidelines Chart for Nonenvironmental Service -240 ENVIRO-SEAL PTFE AND ENVIRO-SEAL DUPLEX HIGH-SEAL GRAPHITE ULF, GRAPHITE ULF, AND BRAIDED GRAPHITE FILAMENT SINGLE AND DOUBLE PTFE V-RING 2000 KALREZ WITH VESPEL CR-6100 (KVSP500) The packing selection guidelines in table 1 present two categories of service conditions. The first category defines packing systems designed for environmental or fugitive emission applications where 100 ppmv (parts per million volume) seal performance is required, using EPA Method 21 per...

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Product Bulletin 59.1:062 December 2018 ENVIRO-SEAL Duplex Packing ENVIRO-SEAL Duplex packing systems were developed, utilizing the benefits of both PTFE and graphite components. These special packing systems provide the capability of graphite packing along with low friction advantages of PTFE packing. Thus, ENVIRO-SEAL Duplex packing systems provide a low friction, low emission, fire-tested solution for applications with process temperatures below 232_C (450_F). ENVIRO-SEAL Duplex packing systems were successfully tested in accordance with API Standard 589, Fire Test Evaluation of Valve...

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Product Bulletin Sliding-Stem Packing Selection Figure 4. Typical Fisher Packing Examples SINGLE PTFE V-RING DOUBLE PTFE V-RING STUD HEX NUT SPRING PACK ASSEMBLY PACKING FLANGE SPACER LANTERN RING LOWER WIPER KALREZ PACKING ASSEMBLY Note: Leak-off tapping and pipe plug are optional.

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Product Bulletin Sliding-Stem Packing Selection Figure 4. Typical Fisher Packing Examples (continued) PACKING FOLLOWER SPRINGS LANTERN RINGS ANTIEXTRUSION WASHERS ANTIEXTRUSION RING PACKING RING ANTIEXTRUSION RING SPRING PACK ASSEMBLY LANTERN RING PACKING RING ENVIRO-SEAL PTFE PACKING WASHERS ENVIRO-SEAL DUPLEX PACKING PACKING FLANGE PACKING BOX STUD FOLLOWER ANTI-EXTRUSION WASHER GRAPHITE BUSHING GUIDE PACKING LANTERN RING ENVIRO-SEAL H2 DUPLEX PACKING Note: Leak-off tapping and pipe plug are optional.

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Product Bulletin Sliding-Stem Packing Selection Figure 5. Typical Fisher Packing Examples LOAD SCALE GUIDE BUSHING PACKING RING PACKING WASHER PACKING RING INDICATOR DISK PACKING FOLLOWER PACKING RING GUIDE BUSHING PACKING RING GUIDE BUSHING PACKING RING GUIDE BUSHING PACKING BOX RING HIGH-SEAL GRAPHITE PACKING RING GUIDE BUSHING PACKING RING GUIDE BUSHING GRAPHITE COMPOSITE DIE-FORMED RIBBON PACKING RING PACKING RING GUIDE BUSHING BRAIDED FILAMENT PACKING WASHER GUIDE BUSHING BRAIDED GRAPHITE FILAMENT Note: Leak-off tapping and pipe plug are optional.

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Product Bulletin 59.1:062 December 2018 Sliding-Stem Packing Selection D101986X012 The HIGH-SEAL graphite ULF packing system is identical to the ENVIRO-SEAL graphite ULF packing system below the packing follower. The primary advantage of the HIGH-SEAL packing system is the use of large diameter Belleville springs. These heavy duty springs offer additional follower travel and can be calibrated with a load scale. The load scale provides a visual indication of packing load as well as packing wear, making it easier for you to determine when additional torquing might be required. HIGH-SEAL...

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