為(wei)了防止無塵(chen)室(shi)(shi)受到污染，室(shi)(shi)內(nei)必須(xu)保持(chi)正壓(ya)(ya)(ya)，如(ru)果(guo)無塵(chen)室(shi)(shi)內(nei)壓(ya)(ya)(ya)力過高，造(zao)成門(men)扇不易開關，因而使用(yong)液(ye)壓(ya)(ya)(ya)閥門(men)來保持(chi)無塵(chen)室(shi)(shi)內(nei)之微(wei)正壓(ya)(ya)(ya)，通過泄壓(ya)(ya)(ya)風(feng)門(men)的風(feng)量一般在(zai)(zai)100-120m3/h之間，保持(chi)壓(ya)(ya)(ya)差在(zai)(zai)5-40Pa之間。