Sempell Model 179 Turbine Drain Valve

The Sempell Model 179 Turbine Drain Valve is a high-performance, forged angle-pattern turbine drain and blowdown valve specifically developed for severe steam service in modern high-pressure and ultra-supercritical power plants. Designed to handle rapid thermal cycling, water hammer, and flashing condensate at pressures up to 400 bar and temperatures to 650 °C, the Model 179 combines a robust Y-pattern forged body with a quick-opening piston actuator and a hardened multi-stage throttle trim (typically 5–7 stages) that provides controlled pressure reduction while minimizing erosion and noise. The valve is normally closed and opens automatically on command from the turbine control system for draining turbine casings, steam lines, and superheater/reheater sections during start-up, shutdown, or trip conditions. Its compact design, low actuator thrust requirement, and optional electric or electro-hydraulic actuation make it the preferred choice for HP, IP, and LP turbine drain systems worldwide

Technical Specification of Sempell Model 179 Turbine Drain Valve

• Type: Forged angle (Y-pattern) piston valve with multi-stage trim
• Sizes: DN 25 to DN 100 (NPS 1 to 4)
• Pressure Rating: Up to PN 720 / ASME Class 4500
• Maximum Inlet Pressure: 400 bar (5800 psig)
• Temperature Range: Up to 650 °C (1200 °F)
• Body Material: Forged A182 F92, F91, F22, WB36 (others on request)
• Trim: Multi-stage pressure reduction (5–7 stages), Stellite or tungsten carbide hardened
• Seat Leakage: ANSI/FCI 70-2 Class V (metal seat)
• Actuator: Pneumatic piston (standard), electric or electro-hydraulic optional
• Operating Time: < 1 second full stroke (pneumatic)
• End Connections: Butt-weld standard (socket-weld or flanged on request)
• Cv Range: 0.5 to 80
• Certifications: ASME Section I, PED 2014/68/EU Cat IV, TR CU, SIL 3 capable

Feature of Sempell Model 179 Turbine Drain Valve

• Die-forged body.
• Bonnet/body one-piece design.
• Stellited seat.
• Guided disk.
• Dust-tight enclosure of actuator head.
• Easy changeover to actuator.
• Position indicator.
• Small driving forces.
• Low pressure loss.
• Easy to maintain.
• 1 or 3 pressure stage(s).