Pressure test method of gate valve

The strength test of the gate valve is the same as that of the stop valve. There are two methods for the sealing test of the gate valve.
① Open the gate to increase the pressure in the valve to the specified value; then close the gate and immediately take out the gate valve to check for leakage at the seals on both sides of the gate or directly inject the test medium into the plug on the valve cover to the specified value , Check the seals on both sides of the gate. The above method is called intermediate pressure test. This method is not suitable for the sealing test of gate valves with a nominal diameter of DN32mm or less.
② Another method is to open the gate to increase the test pressure of the valve to the specified value; then close the gate and open the blind plate at one end to check whether the sealing surface is leaking. Reverse the head and repeat the test above until it is qualified.
Pneumatic gate valve packing and gasket sealing test should be carried out before the gate sealing test.