The strength test of the pressure reducing valve is generally assembled after a single piece test, and it can also be tested after assembly. Strength test duration: more than 3min for DN150mm.
After the bellows and the components are welded, apply 1.5 times the maximum pressure after the pressure reducing valve, and conduct a strength test with air.
The sealing test is carried out according to the actual working medium. When testing with air or water, carry out the test at 1.1 times the nominal pressure; when testing with steam, carry out the test at the highest working pressure allowed under the working temperature. The difference between the inlet pressure and the outlet pressure must not be less than 0.2MPa.
The test method is: after the inlet pressure is adjusted, gradually adjust the adjusting screw of the valve so that the outlet pressure can be changed sensitively and continuously within the range of the maximum and minimum values without stagnation or jamming. For water and air pressure reducing valves, when the inlet pressure is adjusted and the outlet pressure is zero, close the pressure reducing valve and perform a tightness test. If there is no leakage within 2 minutes, it is qualified.
