電(dian)(dian)磁線圈通電(dian)(dian)時，靜(jing)鐵心對動鐵心產(chan)生電(dian)(dian)磁吸力，利用電(dian)(dian)磁力使閥(fa)(fa)芯(xin)切換，以改變氣流方向(xiang)的閥(fa)(fa)，稱為電(dian)(dian)磁控(kong)制(zhi)(zhi)換向(xiang)閥(fa)(fa)，簡(jian)稱電(dian)(dian)磁閥(fa)(fa)。這種閥(fa)(fa)易(yi)于實現電(dian)(dian)-氣聯合控(kong)制(zhi)(zhi)和復(fu)雜控(kong)制(zhi)(zhi)，能(neng)夠遠距(ju)離操作，故得到廣泛(fan)使用。

2）氣(qi)壓(ya)(ya)(ya)(ya)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)：靠氣(qi)壓(ya)(ya)(ya)(ya)力(li)使閥(fa)(fa)芯切換(huan)以改變氣(qi)流方向(xiang)的閥(fa)(fa)稱為氣(qi)壓(ya)(ya)(ya)(ya)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)換(huan)向(xiang)閥(fa)(fa)，簡稱氣(qi)控(kong)(kong)(kong)(kong)(kong)閥(fa)(fa)。這種(zhong)閥(fa)(fa)在易燃、易爆、潮濕、粉塵大、強磁(ci)(ci)場(chang)、高(gao)溫(wen)等(deng)惡劣工(gong)作(zuo)環境(jing)中，以及不(bu)能使用電磁(ci)(ci)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)的環境(jing)中，工(gong)作(zuo)安全可(ke)靠、壽(shou)命長。但氣(qi)壓(ya)(ya)(ya)(ya)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)閥(fa)(fa)的切換(huan)速度比電磁(ci)(ci)閥(fa)(fa)慢。氣(qi)壓(ya)(ya)(ya)(ya)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)可(ke)分成加壓(ya)(ya)(ya)(ya)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)、泄(xie)壓(ya)(ya)(ya)(ya)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)、壓(ya)(ya)(ya)(ya)差控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)和(he)延時(shi)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)。

它是一(yi)種直動(dong)和先(xian)導式相結合(he)的原理，當入(ru)口與出口沒有(you)壓差時，通電(dian)(dian)(dian)后(hou)，電(dian)(dian)(dian)磁力直接把先(xian)導小(xiao)閥(fa)(fa)和主閥(fa)(fa)關(guan)(guan)閉(bi)件(jian)依次向上(shang)(shang)提起(qi)，閥(fa)(fa)門(men)打開(kai)。當入(ru)口與出口達到啟動(dong)壓差時，通電(dian)(dian)(dian)后(hou)，電(dian)(dian)(dian)磁力先(xian)導小(xiao)閥(fa)(fa)，主閥(fa)(fa)下腔(qiang)壓力上(shang)(shang)升，上(shang)(shang)腔(qiang)壓力下降，從而利用(yong)壓差把主閥(fa)(fa)向上(shang)(shang)推(tui)開(kai);斷電(dian)(dian)(dian)時，先(xian)導閥(fa)(fa)利用(yong)彈(dan)簧力或(huo)介質壓力推(tui)動(dong)關(guan)(guan)閉(bi)件(jian)，向下移動(dong)，使閥(fa)(fa)門(men)關(guan)(guan)閉(bi)。

特(te)點:1.在真空、負壓、零壓時能正常工作，但(dan)通徑一般不(bu)超過25mm。

2.在零壓(ya)差或真空、高壓(ya)時(shi)亦(yi)可動作，但功率較(jiao)大，要(yao)求(qiu)必須水平安裝(zhuang)。