H664H pneumatic extraction check valve is used on non corrosive medium pipelines such as water in power plants or thermal power plant extraction systems, or other systems, to prevent sudden pressure drop inside the turbine during turbine stage load, steam backflow from the extraction pipes and various heaters into the turbine, causing severe accidents such as turbine blade breakage and damage to the turbine generator. It also prevents leakage of the heater system pipeline and tightly closes the water extraction system, ensuring that when the water level in the feedwater heater exceeds the limit, the pneumatic device components receive a liquid backflow signal and quickly isolate the turbine, providing good protection for the turbine or extraction system.
The air source comes from compressed air (air source pressure 0.4~0.6Mpa), which enters the two position three-way solenoid valve through a ball valve, and then enters the cylinder inlet through a quick release valve, and the check valve opens. The manual directional valve is used for testing the flexibility of the check valve during operation.
When the check valve is closed, the solenoid valve loses power and closes, cutting off the air source. The quick release valve starts and exhausts the air in the lower chamber of the cylinder, and the check valve quickly closes.
Control components such as solenoid valves and air handling components are imported from ASCO in the United States according to the requirements of the steam turbine factory. Other high-quality products from domestic and foreign manufacturers can also be equipped according to user requirements to ensure excellent performance and high reliability.
H664H Pneumatic Extraction Check Valve Structural Features:
1. The sealing surface is welded with Cr13 series stainless steel or cobalt based hard alloy, which has good wear resistance and stable and reliable sealing performance.
2. When the medium flows forward, the intake air in the lower chamber of the cylinder works together with the heavy hammer, and the closing valve disc is balanced in the fully open position. When the medium flows in the opposite direction, the lower chamber of the cylinder piston quickly releases pressure, and the valve disc quickly closes within 0.5 seconds.
3. The heavy hammer acts on the pin shaft through an extension rod and a shift fork to balance the heavy torque of the rocker arm and prevent the occurrence of water hammer phenomenon. When the medium flows forward, it helps to open the valve and maintain its stability and reduce vibration during operation.

H664H Pneumatic Extraction Check Valve Performance Specification:

Main component materials: