Various valve pressure test methods (three)

Various valve pressure test methods (three)
1. Pressure test method of gate valve
The strength test of the gate valve is the same as that of the globe valve. There are two methods for the sealing test of gate valves.
① Open the gate to raise the pressure in the valve to the specified value; then close the gate, take out the gate valve immediately, check whether there is 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 sealing tests on gate valves with nominal diameters below DN32mm.

② Another method is to open the gate to raise the test pressure of the valve to the specified value; then close the gate, open one end of the blind plate, and check whether the sealing surface is leaking. Then turn the head down and repeat the above test until it is qualified. The sealing test of the pneumatic gate valve packing and gasket should be carried out before the gate sealing test.

2. Pressure test method of safety valve
① The strength test of the safety valve is the same as other valves, and it is tested with water. When testing the lower part of the valve body, the pressure is introduced from the inlet I=I end, and the sealing surface is closed; when testing the upper part of the valve body and the bonnet, the pressure is introduced from the outlet El end, and the other ends are closed. It is qualified if there is no leakage of the valve body and bonnet within the specified time.

② For tightness test and constant pressure test, the generally used medium is: steam safety valves use saturated steam as the test medium; valves for ammonia or other gases use air as the test medium; valves for water and other non-corrosive liquids use water as the test medium medium. Nitrogen is often used as the test medium for safety valves in some important positions.

The sealing test is carried out with the nominal pressure value as the test pressure, and the number of times is not less than two. If there is no leakage within the specified time, it is qualified. There are two ways to check for leaks: one is to seal the joints of the safety valve, and use butter to seal the thin paper on the outlet flange. Plastic board or other boards are pasted on the lower part of the outlet flange, water is poured to seal the disc, and it is qualified if there is no bubble in the water. The number of constant pressure and reseating pressure tests of the safety valve shall not be less than 3 times, and it is qualified if it meets the regulations. For various performance tests of safety valves, see GB/T 12242-1989 Safety Valve Performance Test Methods".

Jiangmen Guolong Precision Valve Co.,Ltd had professional management and production team who has over 10 years of working experience in the gas appliance and product development capability.The scope of production covers various kinds of Oven Gas Valve.Gas Stove Valve.home furnace gas valve.Stove Burner and Stove Burner.For more information, please contact us:
Tel :+86-0750-3772216
Mobile Phone :+8613612273195
Email :salesteam@glstovevalve.com