1. Application

This product is installed on the medium pipeline of the extraction system for power station steam turbines with operating temperature ≤425°C, to prevent medium backflow. The extraction check valve is applied to the extraction systems of power plants or thermal power plants. It can close rapidly and tightly. When the water level of the feedwater heater is excessively high, once the pneumatic actuator receives the backflow signal, the valve will quickly isolate the steam turbine to provide maximum protection for the steam turbine and extraction system.

The closing member disc is movably connected via a rocker arm. The disc rotates around the rocker arm so that it can seat accurately on the sealing face of the valve body and achieve good sealing fit. Stellite hard alloy is hard-faced on the valve sealing surface for excellent wear resistance.

The inclined sealing face of the valve body shortens the closing time of the check valve and enables rapid shutoff.

This check valve is equipped with an air cylinder fitted with an internal spring. When the medium flows in the forward direction, air enters the cylinder inlet to compress the spring, holding the disc steadily at the fully open position. When the air supply is cut off, the cylinder exhausts rapidly and the spring resets instantly to close the check valve in a split second.

Adjust the outlet pressure according to the air supply condition of the system to enable the cylinder to fully open the check valve. Air supply pressure range: 0.45～0.8 MPa.