¢Ù The strength test of pressure reducing valve is generally assembled after single piece test, and it can also be tested after assembly. The duration of strength test: 1 min for DN < 50 mm; 2 min for DN 65-150 mm; 3 min for DN > 150 mm. After the bellows are welded with the components, the strength test shall be conducted with air at 1.5 times of the maximum pressure after the application of pressure reducing valve.
¢Ú The sealing test shall be conducted according to the actual working medium. When using air or water, the test shall be conducted at 1.1 times of the nominal pressure; when using steam, the test shall be conducted at the maximum allowable working pressure under the working temperature. The difference between inlet pressure and outlet pressure shall not be less than 0.2MPa. The test method is: after the inlet pressure is set, gradually adjust the adjusting screw of the valve, so that the outlet pressure can change sensitively and continuously in the range of maximum and minimum, without stagnation and jamming. For the steam pressure reducing valve, when the inlet pressure is adjusted, close the block valve behind the valve, and the outlet pressure is the highest and lowest value. Within 2 minutes, the appreciation of the outlet pressure should meet the provisions in table 4.176-22, and the volume of the pipe behind the valve should meet the provisions in table 4.18. For the water and air pressure reducing valve, when the inlet pressure is adjusted and the outlet pressure is zero, close the pressure reducing valve for sealing The test is qualified if there is no leakage within 2 minutes.
Post time: Apr-20-2021
