1.Gate valve pressure test method
Gate valve strength test and the same as the cut-off valve. There are two ways to test the sealing performance of a valve.
① Gate open, so that the valve pressure rose to the specified value; and then close the gate and immediately remove the gate valve, check the seal on both sides of the gate leakage or directly to the plug on the plug into the test medium to the specified value , Check the seal on both sides of the gate. The above method is called intermediate test pressure. This method should not be nominal diameter DN32mm below the gate valve sealing test.
② Another method is to open the gate, so that the valve test pressure rose to the specified value; and then shut the board, open the blind side, check the sealing surface for leakage. And then down, for more than repeat the test until qualified.
Pneumatic gate valve packing and gasket sealing test should be sealed in the gate before the test.
2.Ball valve test pressure method
Pneumatic ball valve strength test should be in the semi-open state of the ball.
① Floating ball valve sealing test: the valve is half open state, one end of the introduction of test media, the other end closed; the ball a few times, the valve is closed to open the closed end of the inspection, and check the packing and gasket sealing performance, There shall be no leakage. The test medium is then introduced from the other end, and the test described above is repeated.
② Fixed ball valve sealing test: the ball no-load rotation before the test a few times, the fixed ball valve is turned off from one end of the introduction of test media to the specified value; with the pressure gauge to check the introduction of sealing performance, the use of pressure gauge accuracy 0 .5 ~ 1, the range for the test pressure of 1.6 times. In the prescribed time, there is no step-down phenomenon is qualified; then from the other side into the test medium, repeat the test. Then, the valve in a half-open state, both ends closed, cavity filled with the media, under test pressure in the filler and gasket, no leakage.
③ Three-way ball valve should be sealed in various locations on the test.
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