Cold reheat check valve

Application

 

For a thermal power plant with reheating design, a reliable and robust coal reheat check valve is required to protect turbine from damage caused by backflow of high pressure turbine exhaust during turbine trip or load rejection. Check valve prevents reheat steam returning to turbine on trip. And when turbine bypass system is in use, it isolates bypass steam and water from high pressure exhaust.

 

Operation

 

In normal operation, cold reheat check valve is always open and allows high pressure turbine exhaust going to reheater. When pressure inside high pressure turbine goes down during trip or load rejection, it could close quickly and tightly to prevent reverse flow.

 

Features

 

• Free swing valve disc.
• Inclined seat and lower gravity center of tilting disc for short travel and quick closure.
• Wide, flat, non-jamming valve seat for tight sealing.
• Hard sealing surface cladded with alloy for higher resistance for wearing.
• Minimized pressure drop for overall efficiency.
• Reliable open & close action for frequent startup and shutdown of power generation unit.
• Optimized counterweight to allow fully open disc.
• Bolted bonnet for easier maintenance.

 

Specification

 

Standard: ASME/ANSIB16.34
Connection: butt weld or flange
Pressure: PN16～PN420
Size: DN80～1000

 

Material:

 

1、WCB
2、ZG20CrMo、ZG15Cr1Mo1V
3、ASTM A216 WCB
4、ASTM A217 WC6、ASTM A217 WC9
Temperature:
1、WCB：-29℃~425℃
2、Alloy steel：-29℃-540℃、-29℃-570℃