1. Catalogs
  2. FISHER REGULATORS
  3. Sliding-Stem Packing Selection

Sliding-Stem Packing Selection

Sliding-Stem Packing Selection

Sliding-Stem Packing Selection

Product catalog summary
Packing Selection Overview
This document outlines guidelines for selecting packing systems for Fisher sliding-stem valves, highlighting the significance of proper packing selection due to environmental and safety concerns. The guidelines are based on extensive testing to enhance packing performance, reduce maintenance, and extend service life.
Environmental and Regulatory Considerations
Packing selection is influenced by the USA Clean Air Act Amendments and EPA regulations, focusing on reducing emissions and improving seal performance. Factors such as packing friction, hysteresis, seal quality, and cycle life are now considered alongside temperature.
Packing Systems and Applications
The document categorizes packing systems into those suitable for environmental (fugitive emission) applications and non-environmental services. Each system has specific pressure and temperature limits, seal performance, service life, and friction characteristics.
  • Single PTFE V-Ring: Suitable for low-pressure and temperature applications, offering low friction and good seal performance.
  • ENVIRO-SEAL PTFE: Designed for high-stress applications, compensating for imperfections and providing excellent sealing capability.
  • ENVIRO-SEAL Duplex: Combines PTFE and graphite for low friction and low emission, suitable for temperatures below 232°C (450°F).
  • ENVIRO-SEAL H2 Duplex: For high-pressure applications requiring low emissions, using PTFE with carbon-reinforced adaptors.
  • KALREZ with Vespel CR-6100: Offers high temperature resistance with low stress requirements, suitable for various valve sizes.
  • ENVIRO-SEAL Graphite ULF: Designed for high-temperature environmental applications, incorporating PTFE for lubrication and reduced friction.
  • HIGH-SEAL Graphite ULF: Similar to ENVIRO-SEAL Graphite ULF but with larger springs for additional follower travel and load indication.
Figures and Tables
Figures and tables provide detailed pressure and temperature guidelines for each packing system, along with visual examples of typical packing arrangements, aiding in understanding application limits and performance characteristics.
Conclusion
The bulletin emphasizes the importance of selecting the appropriate packing system based on specific application requirements, considering both environmental and non-environmental factors. Proper selection can lead to improved performance, reduced emissions, and lower maintenance costs.
Introduction
The document discusses the advantages of using ENVIRO-SEAL and HIGH-SEAL packing systems to extend the service life of valves, especially under high pressure and temperature conditions, offering improved performance over traditional packing arrangements.
Specifications and Performance
ENVIRO-SEAL packing systems provide enhanced performance compared to traditional single PTFE V-ring or braided graphite filament arrangements. For example, in a CL1500 (HP valve) application at 138 bar and 93°C, the HIGH-SEAL packing system with PTFE washers significantly reduces maintenance needs. This system is rated to 290 bar and 371°C, while the ENVIRO-SEAL system is rated to 207 bar and 371°C.
Installation Considerations
HIGH-SEAL packing systems have a disadvantage during installation as the actuator cannot be removed without removing the Belleville springs, and process pressure must be released before doing so.
Limitations of Traditional Packing
The braided graphite filament arrangement is limited to 103 bar and is prone to breakdown and compression over time, leading to loss of sealing force and potential process control deviations.
Conclusion
Seal performance and service life are influenced by various parameters, including stem finish and installation practices. Emerson's development of ENVIRO-SEAL and HIGH-SEAL packing systems provides opportunities for improved packing selection, resulting in increased service life and reduced maintenance.
Additional Information
For more detailed engineering discussions, Emerson offers Technical Monograph TM-38 on Control Valve Packing Systems. Contact Emerson sales offices for further information.
Disclaimer
The publication is for informational purposes only and does not constitute warranties or guarantees. Emerson reserves the right to modify product designs or specifications without notice.
See more

Catalog excerpts

Sliding-Stem Packing Selection-1

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

 Open the catalog to page 1
Sliding-Stem Packing Selection-2

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. The...

 Open the catalog to page 2
Sliding-Stem Packing Selection-3

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 ANSI/FCI...

 Open the catalog to page 3
Sliding-Stem Packing Selection-4

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 Stem...

 Open the catalog to page 4
Sliding-Stem Packing Selection-5

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.

 Open the catalog to page 5
Sliding-Stem Packing Selection-6

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.

 Open the catalog to page 6
Sliding-Stem Packing Selection-7

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.

 Open the catalog to page 7
Sliding-Stem Packing Selection-8

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 packing...

 Open the catalog to page 8

All FISHER REGULATORS catalogs and technical brochures

  1. R Series

    2  Pages

  2. LP-31

    96  Pages

  3. CS 200 series

    2  Pages

  4. 1301F, 1301G

    12  Pages

  5. MR95 and MR98

    2  Pages

  6. 630 Regulator

    16  Pages

  7. S200 series

    32  Pages

  8. R622 series

    8  Pages

  9. cs200 series

    40  Pages

  10. CS400 Series

    60  Pages

*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.