The safety valve sealing test, as known as safety valve leaking test, is one of the three major test items in the safety valve calibration process. It is designed to evaluate the safety valve sealing performance, thereby ensuring that the safety valve can effectively seal and avoid medium leakage during normal operation.
Two Methods for Safety Valve Sealing Test
1. Hydro test method for safety valve leaking test. It uses clean water as the testing medium. Firstly, pressurize the water to a certain pressure, typically 1.1 times the nominal pressure of the safety valve. And inject it into the safety valve and maintain the pressure for more than 5 minutes. Then visually observe whether the safety valve leaks. This method is very intuitive, but after the test, you must clean up the water remaining in the safety valve in time to avoid residual moisture corroding the safety valve.
2. Pneumatic test method for safety valve leaking test. It adopts air or nitrogen as the testing medium. Firstly, pressurize gas to a certain pressure, usually 1.1-1.25 times the nominal pressure of the safety valve. And inject it into the safety valve and maintain the pressure for at least 5 minutes. Then you can determine if the safety valve is leaking by monitoring the pressure drop with a pressure gauge or by checking for bubbles with soapy water. Due to the much stronger diffusion of gas than water, and the fact that gas does not corrode or contaminate safety valves, this method is more accurate and widely used.
Both of the above methods rely on whether the safety valve leaks to inversely determine its sealing performance. If you need to accurately measure the safety valve leakage rate, you should use the following method.
Safety Valve Leakage Rate Test
PSV leakage rate test uses air or nitrogen as the testing medium, and also requires a safety valve test bench and a bubble counter.
1. Firstly, place your safety valve on PSV test bench and clamp it firmly. In this way, the sealing disk or threaded adapter that comes with the PSV test bench will tightly block the inlet of the safety valve.
2. Block the outlet of the safety valve with a rubber plug or flange sealing disk, leaving a small hole. Then, connect the bubble counter to the safety valve through the small hole via an air hose.
3. Activate PSV test bench to inject high-pressure air or nitrogen into the safety valve and then maintain the pressure.
4. During the pressure maintaining period, the air or nitrogen leaking from the safety valve enters the water tank of the bubble counter through the air hose, thereby forming bubbles.
5.Set a time period on the bubble counter, for example 1 minute, then the bubble counter will automatically count the number of bubbles. The total number of bubbles recorded by the bubble counter divided by the time is the safety valve leakage rate.
In order to facilitate users carrying out safety valve sealing test and leakage rate test, safety valve pop test and reseating test, we provide both Laser bubble counter and PSV testers. Please contact us for brochures.
