Ball valve working principle and pressure test method
Bundor Valve today shares how ball valves work and how to test pressure. Ball valves are common valves:
Ball valve working principle
Ball valve is a ball with a circular channel as the opening and closing parts, the ball with the stem rotation to achieve the opening and closing action of the valve.The opening and closing member of the ball valve is a perforated sphere that rotates around the axis perpendicular to the channel to achieve the purpose of opening and closing the channel.
Ball valve function
Ball valves are mainly used to open and close pipelines and equipment medium, mainly for quick switching fluid.Because the switch degree is not easy to accurately adjust control, so it is not suitable for flow regulation.
Pressure test method
The strength test of the pneumatic ball valve should be carried out with the ball half-open.
Sealing test of floating ball valve:
Put the valve in a half-open state, introduce one end into the test medium, and close the other end; rotate the sphere several times, open the closed end when the valve is closed, and check the sealing performance of the packing and gasket. There must be no leakage. Then introduce the test medium from the other end and repeat the test.
Sealing test of fixed ball valve:
Before the test, the ball was rotated several times with no load, the fixed ball valve was closed, and the test medium was introduced from one end to the specified value; the sealing performance of the lead-in end was checked with a pressure gauge, and the accuracy of the pressure gauge was 0.5 to 1 level. The range was 1.5 times the test pressure.
Within the specified time, if there is no pressure drop, 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, the two ends are closed, and the inner cavity is filled with the medium. Check the packing and gasket under the test pressure, there must be no leakage.
Three-way ball valves shall be tested for leak tightness at all positions.