Pressure Test Method Of Pressure Reducing Valve

① The pressure reducing valve is generally assembled after shell pressure testing, and it can also be tested after assembly. Shell test duration: 1min for DN<50mm; more than 2min for DN65～150mm; more than 3min for DN>150mm. For Bellow Type Pressure Reducing valve, the shell test pressure should be 1.5 times of the max outlet pressure and conducted the shell test with air.

② The sealing test shall be carried out according to the actual working medium. When testing with air or water, perform the test at 1.1 times the nominal pressure; when testing with steam, perform the test at the highest allowable working pressure at 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 change sensitively and continuously within the range of the maximum and minimum values, without stagnation or jamming.

For the steam pressure reducing valve, after the inlet pressure is adjusted, the valve is shut off and the outlet pressure is the highest and lowest value. Within 2 minutes, the rise in the outlet pressure should meet the requirements in Table 4.176-22. At the same time, the pipeline behind the valve The volume meets the requirements in Table 4.18 as qualified; 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.