The requirements for pressure test before the installation of fully welded ball valves mainly include the following aspects:
The strength test uses water as the medium; after the valve is opened to the 45-degree position, water is injected into the fully welded ball valve through the pressure test valve on the sleeve tube, and the pressure is increased to 1.5 times nominal pressure of the ball valve, and the pressure is maintained for 15 minutes.
No leakage is qualified.
The tightness test uses nitrogen as the medium.
Close the ball valve, inject nitrogen into the ball valve from the pressure test valve on the sleeve tube, and the pressure rises to 1.1 times nominal pressure of the fully welded ball valve.
The middle cavity pressure relief valve is connected to the hose and passed into the water container for detection, and the insertion depth is 1cm.
No bubble generated within 5min is qualified.