(1) Floating ball valve sealing experiment: the valve is kept half-open, one end introduces the experimental medium, and the other end is closed. Rotate the ball several times, open the closed end to check when the valve is closed, check the sealing performance of the packing and gasket, do not leak. Then introduce the experimental media at the other end and repeat the above experiment.
(2) Sealing test of fixed ball valve: rotate the ball several times before the test, close the fixed ball valve, and attract the experimental medium to the specified value at one end. Check the sealing performance of the pressure gauge inlet, the accuracy of the pressure gauge is 0.5 ~ 1, and the range is 1.5 times the experimental pressure. Within the specified time, no blood pressure phenomenon is qualified. Then introduce the experimental media at the other end and repeat the above experiment. Then, keep the ball valve in a half-open state, with both ends closed, the inner cavity is filled with medium, and when checking the filler and gasket under the experimental pressure, there should be no leakage.
Check valve experimental state: the axis of the lift check valve disc is in a position perpendicular to the horizontal; the axis of the swing check valve channel and the disc axis are in a position approximately parallel to the horizontal line.
During the strength test, the test medium is introduced from the inlet to the specified value, and the other end is closed, and it is qualified to see that the valve body and valve cover have no leakage.
In the sealing test, the test medium is introduced from the outlet end, and the sealing surface is checked at the inlet end, and no leakage at the packing and gasket is qualified.
The valve opens and the pressure in the valve rises to the specified value. Then, close the gate, take out the gate valve immediately, check whether there is leakage in the sealing parts on both sides of the gate, or inject the experimental medium directly into the plug of the valve cover, inject the specified value, and then check the sealing parts on both sides of the gate.
The strength test of the pneumatic butterfly valve is the same as that of the globe valve. The sealing performance test of the butterfly valve needs to introduce the experimental medium into the medium flow, the butterfly plate is opened, the other end is closed, and the pressure is injected into the specified value. After checking the filler and other sealing parts for leakage, close the butterfly plate, open the other end, and check whether the butterfly plate seal is qualified for leakage. Butterfly valves for flow regulation are not tested for sealing performance.
The strength test of the safety valve is the same as other valves, which is tested with water. When testing the lower part of the valve, the pressure enters from the I=I side, and the sealing surface is closed. When testing valve tops and valve caps, pressure enters from one end and closes the other end. The phenomenon that the valve and the valve do not leak within the specified time is qualified.
The sealing test and static pressure test generally use saturated steam as the experimental medium by the safety valve for steam. Ammonia or other gas valves use air as the test medium. Valves for water and other corrosive liquids use water as the experimental medium. Safety valves in some important positions often use nitrogen as the experimental medium.