Various valve pressure test methods
Teach you various valve pressure test methods Episode 1: How to test the pressure of a ball valve ，other ball valves, pay attention to us .this is our facebook
Under normal circumstances, industrial valves are not subject to strength tests when they are in use, but strength tests should be performed on repaired valve bodies and bonnets or corroded valve bodies and bonnets. For the safety valve, its set pressure, reseating pressure and other tests shall comply with the specifications of its instructions and relevant regulations. The strength and tightness test should be done before the valve is installed. 20% of the low-pressure valves are spot-checked, and 100% of them should be checked if they are unqualified; 100% of the medium and high-pressure valves should be checked. The commonly used media for pressure testing of valves are water, oil, air, steam, nitrogen, etc. The pressure testing methods of various industrial valves including pneumatic valves are as follows:
Pressure test method of ball valve
The strength test of the pneumatic ball valve should be carried out under the half-open state of the ball.
① Floating ball valve sealing test: put the valve in a half-open state, introduce the test medium at one end, and close the other end; rotate the ball several times, open the closed end to check when the valve is in the closed state, and check the sealing performance of the packing and gasket at the same time. There must be no leakage. Then introduce the test medium from the other end and repeat the above test.
②Sealing test of fixed ball valve: Before the test, rotate the ball several times without load, and the fixed ball valve is in the closed state, and introduce the test medium from one end to the specified value; check the sealing performance of the introduction end with a pressure gauge, and use a pressure gauge with an accuracy of 0 ．Class 5~1, the measuring range is 1.5 times of the test pressure. Within the specified time, if there is no depressurization phenomenon, it is qualified; then introduce the test medium from the other end, and repeat the above test. Then, the valve is in a half-open state, both ends are closed, and the inner cavity is filled with medium. Check the packing and gasket under the test pressure, and there must be no leakage.
③ Three-way ball valves should be tested for tightness at each position.
