Bulletin 71.2:92B September 2014 Type 92B Pressure Reducing Valve • Extended Diaphragm Service Life • Two-Path Control • Elevated Actuator • Resilient Seats • Bellows Stem Guide • Double Post Stem Guide W8264 • Standard ANSI Face-to-Face Life D101342X012 Figure 1. Type 92B Pressure Reducing Valve www.fisherregulators.
Bulletin 71.2:92B Introduction The Type 92B Pressure Reducing Valve is the standard steam valve for industry. The Type 92B is designed to provide decades of continuous service. It can withstand dirty operating environments while providing accurate and stable pressure control. The Type 92B is applied as a main Pressure Reducing Valve in industrial process heating applications such as heat exchangers, evaporators, digesters and reactors.
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Bulletin 71.2:92B Specifications This section lists the specifications for the Type 92B Pressure Reducing Valve. The following information is stamped on the nameplate of Type 92B: Type Number, Maximum Outlet Pressure, Maximum Inlet Pressure and Maximum Temperature. Available Configurations Pilot-operated globe-style pressure reducing valve with post guiding and flow-to-close valve plug action.
Bulletin 71.2:92B Table 1. Body Sizes and End Connection Styles END CONNECTION STYLES BODY SIZES, NPS / DN 1 / 25 Cast iron Body NPT 1-1/2 and 2 / 40 and 50 NPT, CL125 FF and CL250 RF NPT, SWE(1), CL150 RF, CL300 RF and PN 16/25/40 RF Steel and Stainless steel Body 3 and 4 / 80 and 100 CL125 FF and CL250 RF CL150 RF, CL300 RF, PN 16 RF and PN 25/40 RF 1. Available in steel bodies only. Table 2.
Bulletin 71.2:92B CONTROL LINE PILOT SPRING ORIFICE PILOT CONTROL LINE MAIN VALVE DIAPHRAGM PILOT DIAPHRAGM PILOT VALVE PLUG VALVE PLUG MAIN VALVE SPRING PILOT SUPPLY LINE E0672 INLET PRESSURE OUTLET PRESSURE ATMOSPHERIC PRESSURE LOADING PRESSURE Figure 3. Type 92B Operational Schematic Principle of Operation Refer to Figure 3. Compression of the pilot spring pushes diaphragm down and holds pilot valve plug open. Outlet pressure is changed by varying the amount of pilot spring compression.
Bulletin 71.2:92B TYPE 92B PILOT (B) TYPE 92B MAIN VALVE TYPE 92B PILOT (C) TYPE 92B MAIN VALVE TYPE 6492HM SAFETY OVERRIDE PILOT (A) E0794 INLET PRESSURE OUTLET PRESSURE ATMOSPHERIC PRESSURE LOADING PRESSURE INTERMEDIATE PRESSURE Figure 4. Safety Override System Schematic system, thereby preventing a high differential across the diaphragm which might otherwise cause diaphragm damage.
Bulletin 71.2:92B Installation Installation of the Type 92B is dependent on the application. As a minimum, a typical steam pressure reducing station must include a 3-valve bypass, inlet drip leg, inlet strainer (and steam separator if required) and relief valve per ASME Section VIII code. A safety override pressure reducing station can be installed in the event a relief valve is not practical as per ASME B16.122.14 standards, subject to local codes and regulations.
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Bulletin 71.2:92B TYPE 92B MAIN VALVE TYPE 6492HM SAFETY OVERRIDE PILOT TYPE 92B MAIN VALVE TYPE 92B PILOT TYPE 92B PILOT Top View TYPE 92B MAIN VALVE TYPE 92B MAIN VALVE TYPE 92B PILOT TYPE 92B PILOT TYPE 6492HM SAFETY OVERRIDE PILOT Side View Figure 6. Safety Override System Installation Example: Example Calculation: RELIEF VALVE SET: 15 psig / 1.0 bar FULL OPEN: 25 psig / 1.7 bar Qmax(lb/hr) = 10 psig / 0.69 bar 100 psig / 6.
Bulletin 71.2:92B Table 5. Main Valve Coefficients FLOW COEFFICIENTS BODY SIZE Regulating Coefficients IEC SIZING COEFFICIENTS Wide-Open Coefficients C1 Km NPS DN Cg Cs Cv Cg Cs Cv 1 1-1/2 25 40 330 560 16.5 28 9.4 16 480 921 24 46 13.7 26.3 35 35 2 3 4 50 80 100 960 2000 2700 48 100 135 27.4 57.1 77.1 1481 3042 4515 74 152 225 42.3 86.9 129 35 35 35 FL XT FD 0.80 0.80 0.89 0.89 0.78 0.78 0.24 0.25 0.80 0.80 0.80 0.89 0.89 0.89 0.78 0.78 0.78 0.28 0.26 0.
Bulletin 71.2:92B Table 6. Capacities(1) (continued) INLET PRESSURE OUTLET PRESSURE psig psig bar 20 40 60 1.4 2.8 4.1 4460 4460 4460 2023 2023 2023 7850 7920 8100 3561 3592 3674 13,000 13,200 13,300 5897 5988 6033 27,200 27,300 27,300 12,338 12,383 12,383 37,300 37,800 38,500 16,919 17,146 17,464 80 100 120 150 5.5 6.9 8.3 10.
Bulletin 71.2:92B F - DOWNSTREAM CONTROL LINE CONNECTION, NPT c e n g l 1/2 A A npt F - DOWNSTREAM CONTROL LINE CONNECTION, NPT c E n g l b A flanged Figure 7. Dimensions Table 8. Dimensions DIMENSIONS BODY SIZE A NPT NPS DN L CL125 FF(1) and CL150 RF CL250 RF(1) and CL300 RF PN 16 RF C PN 25/40 RF E G F NPT In. mm In. mm In. mm In. mm In. mm In. mm In. mm N In. mm In. 1 1-1/2 2 25 40 50 6.50 8.00 9.25 165 203 235 7.25 8.75 10.00 184 222 254 7.75 9.25 10.
Bulletin 71.2:92B Ordering Guide Inlet Steam Conditions (Select One) Steel ≤ 125 psig / 8.6 bar; 353°F / 178°C ≤ 175 psig / 12.1 bar; 450°F / 232°C CL150 RF Flanged ≤ 185 psig / 12.8 bar; 450°F / 232°C CL300 RF Flanged ≤ 250 psig / 17.2 bar; 406°F / 208°C ≤ 300 psig / 20.7 bar; 450°F / 232°C ≤ 300 psig / 20.
Bulletin 71.2:92B Ordering Guide (continued) High Temperature Type 6492HTM Pilot Spring Range 15 to 100 psig / 1.0 to 6.9 bar, Unpainted 15 to 100 psig / 1.0 to 6.9 bar, Unpainted 80 to 250 psig / 5.5 to 17.2 bar, Unpainted 80 to 250 psig / 5.5 to 17.
Bulletin 71.2:92B Industrial Regulators Natural Gas Technologies TESCOM Emerson Process Management Regulator Technologies, Inc. Emerson Process Management Regulator Technologies, Inc. Emerson Process Management Tescom Corporation USA - Headquarters McKinney, Texas 75070 USA Tel: +1 800 558 5853 Outside U.S. +1 972 548 3574 USA - Headquarters McKinney, Texas 75070 USA Tel: +1 800 558 5853 Outside U.S.
