泄压持压阀一般分为隔膜阀和活塞阀两大类，本公司生产的泄压持压阀口径在DN400mm以下者采用隔

膜型，口径在DN450mm以上者采用活塞型，两者之动作原理类似。泄压持压阀在给水管线上能有效地将

超过导阀安全设定值的压力泄压释放，防止对管线与设备因超压而损坏。该阀主要用于高层大楼消防测试

Decompression or sustaining valves are usually divided into diaphragm valves and piston valves two categories, the caliber of the  company’s production bellows DN500 using diaphragm type, and DN600 more in the use of piston type, whichever is the principle of similar moves. In the water supply pipeline, decompression and sustaining valves can release the pressure effectively which over the safety valve settings, prevent the pipeline and equipments are damaged by the excess pressure. The valves are mainly used in the decompression of the fire protection test circle system; prevent the system failure because of the excess pressure.