Extraction Steam Check Valve

Detailed product information

The steam extraction check valve is a special high-speed valve designed to protect turbine generator units. It prevents reverse steam flow from the extraction pipes and heat exchangers into the turbine during sudden load shedding, when the pressure in the turbine drops sharply. This eliminates the possibility of reverse rotation of the turbine blades (at speeds exceeding 3000 rpm), which could lead to their destruction and a turbine generator accident. The valve also prevents hydraulic shocks that can occur when water enters the turbine due to leaks in the heater system. In such situations, the valve closes within 0.5 seconds.

Design features

1. The pneumatic check valve is opened by compressed air acting on the piston in the cylinder. The piston rotates the rotary shaft via a fork, opening the valve. The valve is closed by a spring after the air is shut off by a solenoid valve.

2. The sealing surfaces of the valve and seat are made using the latest surfacing materials, which are highly wear-resistant and resistant to scratches.

3. Highly efficient modern packing is used to ensure reliable sealing and ease of operation.

Product parameters

♦ Product standards: JB/T 3595, NB/T 47044, ASME B16.34

♦ Nominal pressure: PN16-PN420 (150LB-2500LB)

♦ Nominal diameter: DN50-DN500 (2“-20”)

♦ Body material:

1. WCB

2. ZG20CrMo, ZG15Cr1Mo1V

3. ASTM A216 WCB

4. ASTM A217 WC6, ASTM A217 WC9

Operating temperature

1. WCB: -29℃ to +425℃

2. Alloy steel: from -29°C to +540°C, from -29°C to +570°C

♦ Working media: water, steam, and others

♦ Connection method: flanged, welded

♦ Control method: pneumatic, hydraulic