A range of high pressure turbine bypass valves that provide greater reliability under extreme conditions. FEATURES Pressure reduction by multi-stage controlled expansion Atomizing steam desuperheater, providing short evaporation length and protection of downstream piping against thermal shock Subsequent adjustment to changed operational conditions possible due to easily exchangeable trim and seat Pressure balanced trim with pilot plug Spring-loaded packing for long term leaktightness Pressure seal bonnet Short delivery times due to modularized design Order-specific optimization of trim flow areas and desuperheater Customized welding ends and transition to piping All actuator types can be used Optional: pre-warming and condensate drain studs GENERAL APPLICATION Steam turbine and boiler protection at steam turbine trip. Steam turbine to cold reheat or condenser while boiler/ turbine startup and shut down. Applied in: - coal fired power plants - natural gas fired power plants TECHNICAL DATA Inlet size: DN150 to DN 500 Outlet size: DN 350 to DN 850 Pressure: up to 320 bar Temperature: up to 620 C Body material: A182-F22, A182-F91 or A182-F92 Range of control: Standard: 1:25 Shut-off class: ASME FCI 70.2 class V Emerson.com/FinalControl 2017 Emerson. All rights reserved. VCTDS-03895-EN 16/03
Spring loaded packing for long term leak tightness Pressure balanced trim with pilot plug - shut-off-class V - sealing achieved solely by the metallic seat - guidings by metal to metal - elimination of soft goods at the moving part of the trim Quickly and easily exchangeable seat Perforated plug /cage low noise and anti-vibration Atomizing steam desuperheater - short evaporation length - thermal shock protection of downstream piping 2
SEMPELL CONVENTIONAL HP BYPASS VALVE The HP Bypass valve is used to discharge steam from the boiler when it cannot be taken by the turbine, i.e. during start-up and shut-down and during plant disturbances. Reliable operation of the HP bypass ensures thermal protection of the intermediate superheater and avoids a triggering of the HP safety valves. During normal operation, the HP bypass valve must be tightly shut to avoid energy loss due to steam leakage. The Sempell conventional HP Bypass valve is based upon decades of design and manufacturing experience with steam conditioning valves. The combination of material selection and multi-stage pressure reduction make the valve highly resistant to wear in spite of extreme working conditions and ensures long a long lifetime of all components. The pressure balanced trim with pilot plug minimizes required actuator thrust and avoids leakage issues by eliminating gaskets at the moving parts of the trim. The desuperheating takes place at the outlet of the valve by means of atomizing steam spray though special nozzles. SHO Superheater outlet safety valve SHO PCV Superheater outlet relief valve HP LP G RHI SV HPB High pressure bypass station SHI RHO SV Reheater outlet safety valve SSSV protection Feed-water-tank LPB Low pressure bypass station DPV Pressure seal test MBG Orifice housing HD-VWA High pressure preheater protection ND-VWA Low pressure preheater protection ATOMIZING STEAM SUPERHEATER Sempellʼs steam assisted desuperheating nozzle is characterized by the central position in the steam flow and the embedding of the injection water in an inner and outer atomizing steam jet. The atomizing steam flow has a much higher velocity than the injection water droplets. This high kinetic energy results in an excellent heat transfer which leads to a rapid evaporation of the injection water drops. Delays in heat up or evaporation of water drops by a saturated steam layer is prevented because the water drops are continuously in direct contact with the superheated steam. The required evaporation length is optimal short. In the last reduction stage of the Sempell Turbine Bypass valve a diffusor plate is used which creates an even outlet flow and eliminates steam vortex forming. The atomizing steam is delivered from the cage plug and does not require a separate assist steam control valve. The atomizing steam jet passes the central nozzle with sonic velocity, hits the injection water and breaks it up to a very fine spray. This fine spray water jet is covered by a second outer cone of assist steam. This cone works like a protection layer and prevents that water drops from contacting the inner pipe wall. As a result, thermal shocks or premature material fatigue in the outlet pipe is avoided. The Sempell steam assisted desuperheating nozzle ensures a very precise temperature control over a wide load range down to smallest of mass flows. Atomizing steam Cooling water Central jet Jacket jet 3
5 1 2 4 3 6 TABLE 1 - MATERIALS Item No. Description Recommended for up to 560 C Recommended for up to 600 C Recommended for up to 620 C 1 Body A 182 F22 A 182 F91 A 182 F92 2 Bonnet A 182 F22 A 182 F91 A 182 F92 3 Seat/cage 1.7380, stellited 1.4903, stellited 1.4903, stellited 4 Plug 1.7380. stellited 1.4903, stellited 1.4903, stellited 5 Stem 1.4922 1.4922 1.4913 6 Outlet A 182 F22 A 182 F22 A 182 F91 4
min. 300 G E Steam D B Cooling water C A TABLE 2 - DIMENSIONS (mm) Valve size Inlet pipe Nominal size Outlet pipe Nominal size A B C D E Valve mass (kg) Hydraulic actuator Pneumatic actuator Electric actuator G (*) Actuator mass (kg) G (*) Actuator mass (kg) HP1 DN 150 - DN 300 DN 350 - DN 500 420 705 345 615 890 1070 750 80 330 300 730 75 DN 400 - DN 550 420 735 375 675 890 1160 750 80 330 300 730 75 HP2 DN 200 - DN 400 DN 500 - DN 650 550 864 425 863 992 2034 750 80 350 450 680 70 DN 600 - DN 750 550 898 470 942 992 2174 750 80 350 450 680 70 HP2L DN 200 - DN 450 DN 500 - DN 650 550 896 425 895 1183 2850 750 110 350 475 880 110 DN 600 - DN 750 550 926 475 975 1183 3030 750 110 350 475 880 110 HP3 DN 250 - DN 500 DN 600 - DN 750 600 943 470 987 1233 3330 750 160 370 475 880 110 DN 700 - DN 850 600 983 520 1077 1233 3540 750 160 370 475 880 110 G (*) Actuator mass (kg) (*) Approximate value, actuator height pending order specific detailed engineering 5
TABLE 3 - CAPACITY AND PERFORMANCE DATA Valve size HP1 HP2/HP2L HP3 Seat mm 110 130 155 180 205 235 Max Capacity (C v ) Gal/min 245 364 549 744 997 1329 K v m³/h 209 311 469 636 852 1136 stroke mm 70 70 80 90 110 110 Flow coefficient Flow coefficient Stroke Stroke TABLE 4 - APPLICATION LIMITS design temperature ( C) Valve 390 410 430 450 470 490 510 530 550 570 585 600 610 620 630 size Class Material max. design pressure (bar g) HP1 2850 F22 463 463 460 448 414 366 307 244 185 137 107 0 0 0 0 F91 478 474 466 448 414 366 322 288 275 272 255 231 208 185 162 F92 478 474 466 448 414 366 322 288 275 272 264 254 239 224 205 HP2 2850 F22 463 463 460 448 414 366 307 244 185 137 107 0 0 0 0 F91 478 474 466 448 414 366 322 288 275 272 255 231 208 185 162 F92 478 474 466 448 414 366 322 288 275 272 264 254 239 224 205 HP2L 3750 F22 609 609 605 589 545 481 404 321 243 180 141 0 0 0 0 F91 629 623 613 589 544 481 423 378 361 357 335 303 273 243 213 F92 629 623 613 589 544 481 423 378 361 357 347 334 314 294 269 HP3 3750 F22 609 609 605 589 545 481 404 321 243 180 141 0 0 0 0 F91 629 623 613 589 544 481 423 378 361 357 335 303 273 243 213 F92 629 623 613 589 544 481 423 378 361 357 347 334 314 294 269 6
SELECTION GUIDE Example 115N-CHP 0150 HP1 0350 63 S B 3 110 Valve model 115N-CHP Press balance + pilot disc without springs 115M Press balance + pilot disc with springs Inlet nominal size 0150 DN 150 (NPS 6) 0200 DN 200 (NPS 8) 0250 DN 250 (NPS 10) 0300 DN 300 (NPS 12) 0350 DN 350 (NPS 14) 0400 DN 400 (NPS 16) 0450 DN 450 (NPS 18) 0500 DN 500 (NPS 20) Valve size HP1 HP2 HP2L HP3 Outlet nominal size 0350 DN 350 (NPS 14) 0400 DN 400 (NPS 16) 0450 DN 450 (NPS 18) 0500 DN 500 (NPS 20) 0550 DN 550 (NPS 22) 0600 DN 600 (NPS 24) 0650 DN 650 (NPS 26) 0700 DN 700 (NPS 28) 0750 DN 750 (NPS 30) 0800 DN 800 (NPS 32) Material specification 63 Body A182F22 80 Body A182F91 84 Body A182F92 Pipe connection S Welding end Steam bypass B Steam desup. orifice Stages 3 3 stages Seat diameter 110 Ø 110 130 Ø 130 155 Ø 155 180 Ø 180 205 Ø 205 235 Ø 235 260 Ø 260 7
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