The H664H/H644 pneumatic exhaust check valve is used in power plants or thermal power plants for suction systems, or other non-corrosive medium pipelines, such as water, to prevent sudden pressure drop in the steam turbine stage, causing steam backflow into the turbine and potentially damaging it, as well as to prevent catastrophic failures in steam turbine generators. It also helps prevent leaks in the heating system pipelines, ensuring tight closure of water from steam extraction. It guarantees that when the hot water heater is over-pressurized, the pneumatic device components connect to the liquid backflow signal, causing the turbine to quickly disconnect, providing excellent protection for the turbine or pump system.

The gas source is compressed air (pressure range: 0.4~0.6 Mpa), which enters the two-way three-way solenoid valve via a ball valve. It then flows through a quick exhaust valve into the cylinder intake, and the check valve opens. A manual directional valve is used to test the flexibility of the check valve.

When the check valve closes, the solenoid valve is de-energized and closed, the gas source is cut off, the quick exhaust valve is activated, the air in the lower cavity of the cylinder is exhausted, and the check valve closes quickly.

Electromagnetic valves and air handling components, among other control components, are imported from the U.S. ASCO as per the requirements of the steam turbine manufacturer. Products from other domestic and international suppliers can also be provided upon customer request to ensure performance and high reliability.

Pneumatic exhaust check valve features:

The sealing surface is焊接with Cr13 stainless steel or cobalt-based hard alloy, offering excellent wear resistance and stable, reliable sealing performance.

2. As the medium flows forward, air in the lower cylinder chamber combines with weight, balancing the valve disc in the fully open position. When the medium flows in the opposite direction, the lower cylinder chamber of the piston rapidly releases pressure, and the valve disc closes quickly within 0.5 seconds.

3. Apply weight to the pinion shaft via the extended rod and front fork to balance the lever weight and prevent water hammer. It assists in opening the valve and maintaining stability, as well as reducing vibration during operation when the medium moves forward.