Extraction check valve

1、 Purpose:
This product is used on the medium pipeline of the extraction system of power plant steam turbines with a working temperature of ≤ 425 ° C, as a device to prevent medium backflow. Exhaust check valve is used in the exhaust system of power plants or thermal power plants. It quickly and tightly closes to ensure that when the water level in the feedwater heater is high, once the pneumatic device components receive a liquid backflow signal, they quickly isolate the turbine and provide great protection to the turbine or exhaust system.
2、 Structural description
The closing valve disc is connected by a rocker arm, and the valve disc rotates around the rocker arm to accurately land on the sealing surface of the valve body, ensuring a fit with the valve. The valve sealing surface is welded with Stellite hard alloy, which has good wear resistance.
The valve body sealing surface is inclined to reduce the closing time of the check valve and ensure quick closure.
The check valve is equipped with a cylinder, which contains a spring. When the medium flows in the positive direction, the cylinder's intake port is filled with air, compressing the spring to keep the valve disc relatively stable in the fully open position; When the gas source is turned off, the cylinder quickly releases pressure, the spring quickly resets, and the check valve instantly closes.
Adjust the outlet pressure according to the system air supply situation to fully open the check valve of the cylinder.
The gas source pressure is within the range of 0.45-0.8MPa.
3、 Precautions for storage, installation, use, and maintenance

1. Check valves should be stored in a dry warehouse, with both ends of the groove coated with anti rust paint and sealed tightly, and should not be stacked outdoors.

2. When storing, do not use the cylinder to support the weight of the check valve to prevent the cylinder rod from bending.

3. Before installation, check the nameplate and valve body markings to ensure they meet the requirements. Before installation, check whether the two end covers are intact and pay attention to no foreign objects falling in.

4. Note that the flow direction arrow is consistent with the flow direction of the medium.

　　　　　Exhaust check valve                     　　　　　　　　High exhaust check valve