Thread Content
Pressure relief valves are frequently used in regular production, and several factors should be taken into account when selecting them. Pressure relief valves are suitable for compressed air, steam, water, industrial gases, oils, and other liquid media. Therefore, given these many possible structural changes, when considering the selection of a pressure relief valve, the most important factor is its actual performance; thorough testing should be carried out first to ensure good performance in use. During testing, the pressure relief valve shall meet the following performance requirements: ① Within the given range of spring pressure levels, the outlet pressure must be able to be adjusted continuously between its maximum and minimum values, without any sticking or abnormal vibrations. ②For pressure relief valves with soft seals, there must be no leakage over a specified period of time; for those with metal seals, the leakage rate shall not exceed 0.05% of the maximum flow rate. ③When the outlet flow rate changes, the negative deviation of the outlet pressure shall not exceed 20% for direct-acting types and 10% for pilot-operated types. ④When the inlet pressure changes, the deviation in the outlet pressure shall be no more than 10% for direct-acting types, and no more than 5% for pilot-operated types. ⑤For pressure relief valves that are not in use, adjust the spring to put it in a relaxed state. The inlet and outlet ends should be covered and sealed.