止回閥的結構特點與功能作用
止(zhi)(zhi)(zhi)回(hui)閥(又(you)稱逆止(zhi)(zhi)(zhi)閥或單向閥)是防止(zhi)(zhi)(zhi)流(liu)(liu)體倒(dao)流(liu)(liu)的閥,從結構分(fen)類,有升(sheng)降式(shi)、旋啟式(shi)、彈簧式(shi)和(he)蝶式(shi)等幾種止(zhi)(zhi)(zhi)回(hui)閥。①.升(sheng)降式(shi)止(zhi)(zhi)(zhi)回(hui)閥(見圖4-35)升(sheng)降式(shi)止(zhi)(zhi)(zhi)回(hui)閥的閥芯可(ke)上(shang)下自(zi)由移動,流(liu)(liu)體應(ying)由下而上(shang)推開閥芯,當閥芯下部人(ren)口壓力(li)小于(yu)上(shang)部出口壓力(li)時(shi),閥芯靠自(zi)重及上(shang)部流(liu)(liu)體壓力(li)的雙重作用...