Pilot-operated safety valve

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This post was last edited by rwq on 2010-3-8 at 19:59. It consists of a main valve and a pilot valve; the main valve is the actual safety valve, while the pilot valve is used to detect changes in system pressure, thereby controlling the opening or closing of the main valve according to the specified pressure. When the system pressure reaches the set value, the pilot valve opens automatically to release the pressure at the top of the main valve; thereafter, the main valve opens to discharge any excess pressure from the system. Features of pilot-operated safety valves: 1) The pilot valve is highly sensitive to changes in system pressure ； 2) The volume is relatively smaller compared to the spring type ； 3) High gas emissions ； Problems with pilot-operated safety valves: 1) High cost, approximately 1.5 times that of spring-loaded safety valves ； 2) An O-ring is used for sealing; after startup, impurities can damage the O-ring, so it needs to be removed and replaced in order to reset the pressure. Once the spring-loaded safety valve opens, its seal generally does not get damaged easily, allowing it to continue to be used. 3) It is troublesome to maintain a constant pressure, and there are few qualified calibration units available. Spring-type safety valves can be calibrated by any regular maintenance facility.