Fully welded trunnion pipeline ball valve must be tested before being used. They are installed on a variety of pipeline projects. And if there is a problem in performance, the work of entire pipeline will be affected.
Sealing performance test: Nitrogen is medium in sealing test. The step of test is as following: First of all, we should turn off the ball valve. Secondly, it is needed to inject nitrogen from the sleeve, through the valve that tests pressure, into the full welded ball valve, which makes the pressure become 1.1 times higher than specified nominal pressure. And then through the hose join nitrogen up to the container with water to detect(The depth of water is about 1 cm and the time is about 5 min.)
Strength test: Water is medium in the strength test. Weld high-pressure caps at both ends of valve and open ball valve to make the ball be at 45°position. Then inject water to welding ball valve, using testing-pressure valve at both sides of sleeve, to make pressure become 1.5 times higher than specified nominal pressure of welding ball valve and pressure 15 min. If there is no medium leakage, it shows that zero leakage is normal.