減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)按動(dong)作原理分為直接(jie)作用(yong)(yong)(yong)(yong)(yong)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)和先(xian)導(dao)(dao)(dao)式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)。直接(jie)作用(yong)(yong)(yong)(yong)(yong)式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)是利用(yong)(yong)(yong)(yong)(yong)出口(kou)(kou)(kou)(kou)壓(ya)力的(de)(de)(de)(de)變(bian)化直接(jie)空(kong)(kong)中(zhong)(zhong)閥(fa)(fa)(fa)瓣的(de)(de)(de)(de)運動(dong)。波紋(wen)管直接(jie)作用(yong)(yong)(yong)(yong)(yong)式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)適(shi)用(yong)(yong)(yong)(yong)(yong)于(yu)(yu)低(di)壓(ya)、中(zhong)(zhong)小(xiao)(xiao)(xiao)口(kou)(kou)(kou)(kou)徑(jing)的(de)(de)(de)(de)蒸(zheng)汽介(jie)質(zhi)(zhi)、薄膜直接(jie)作用(yong)(yong)(yong)(yong)(yong)式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)適(shi)用(yong)(yong)(yong)(yong)(yong)于(yu)(yu)中(zhong)(zhong)低(di)壓(ya)、中(zhong)(zhong)小(xiao)(xiao)(xiao)口(kou)(kou)(kou)(kou)徑(jing)的(de)(de)(de)(de)空(kong)(kong)氣、水(shui)介(jie)質(zhi)(zhi)。先(xian)導(dao)(dao)(dao)式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)有導(dao)(dao)(dao)閥(fa)(fa)(fa)和主(zhu)閥(fa)(fa)(fa)組成，出口(kou)(kou)(kou)(kou)壓(ya)力的(de)(de)(de)(de)變(bian)化通過導(dao)(dao)(dao)閥(fa)(fa)(fa)放大來(lai)控(kong)制(zhi)主(zhu)閥(fa)(fa)(fa)閥(fa)(fa)(fa)瓣的(de)(de)(de)(de)運動(dong)。先(xian)導(dao)(dao)(dao)活塞式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)，適(shi)用(yong)(yong)(yong)(yong)(yong)于(yu)(yu)各種壓(ya)力、各種口(kou)(kou)(kou)(kou)徑(jing)、各種溫度(du)的(de)(de)(de)(de)蒸(zheng)汽、空(kong)(kong)氣和水(shui)介(jie)質(zhi)(zhi)。若(ruo)用(yong)(yong)(yong)(yong)(yong)不銹耐酸鋼制(zhi)造(zao)，可適(shi)用(yong)(yong)(yong)(yong)(yong)于(yu)(yu)各種腐蝕形介(jie)質(zhi)(zhi)。先(xian)導(dao)(dao)(dao)波紋(wen)管式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)，適(shi)用(yong)(yong)(yong)(yong)(yong)于(yu)(yu)低(di)壓(ya)、中(zhong)(zhong)小(xiao)(xiao)(xiao)口(kou)(kou)(kou)(kou)徑(jing)的(de)(de)(de)(de)蒸(zheng)汽、空(kong)(kong)水(shui)等介(jie)質(zhi)(zhi)。先(xian)導(dao)(dao)(dao)薄膜式(shi)(shi)減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)適(shi)用(yong)(yong)(yong)(yong)(yong)于(yu)(yu)中(zhong)(zhong)壓(ya)、低(di)壓(ya)，中(zhong)(zhong)小(xiao)(xiao)(xiao)口(kou)(kou)(kou)(kou)徑(jing)的(de)(de)(de)(de)蒸(zheng)汽或水(shui)等介(jie)質(zhi)(zhi)。減(jian)(jian)(jian)(jian)(jian)壓(ya)閥(fa)(fa)(fa)進口(kou)(kou)(kou)(kou)壓(ya)力的(de)(de)(de)(de)波動(dong)應控(kong)制(zhi)在進口(kou)(kou)(kou)(kou)壓(ya)力給定值(zhi)的(de)(de)(de)(de)80%～105%，如(ru)超過該(gai)范圍，減壓(ya)閥(fa)(fa)的性(xing)能會受影響(xiang)。通常(chang)減壓(ya)閥(fa)(fa)的閥(fa)(fa)后壓(ya)力Pc應小于閥前壓力(li)的0.5倍，即Pc<0.5P1。減壓(ya)(ya)閥的(de)每一檔彈(dan)(dan)簧只在一定的(de)出口壓(ya)(ya)力范圍內適用，超出范圍應(ying)更換彈(dan)(dan)簧。