擴(kuo)(kuo)散泵(beng)：以(yi)低壓(ya)高速蒸(zheng)(zheng)(zheng)(zheng)汽流（油(you)或等蒸(zheng)(zheng)(zheng)(zheng)汽）作為工(gong)(gong)作介(jie)質(zhi)的(de)(de)(de)噴射真空(kong)泵(beng)。氣體分(fen)子擴(kuo)(kuo)散到蒸(zheng)(zheng)(zheng)(zheng)汽射流中，被送(song)到出口。在(zai)射流中氣體分(fen)子密度始終是很低的(de)(de)(de)，這(zhe)種(zhong)(zhong)(zhong)泵(beng)適(shi)于(yu)在(zai)分(fen)子流狀態(tai)下工(gong)(gong)作。可分(fen)為：① 自凈化擴(kuo)(kuo)散泵(beng)：泵(beng)液(ye)中易揮發的(de)(de)(de)雜質(zhi)經(jing)專門的(de)(de)(de)機械輸(shu)送(song)到出口而不回到鍋爐中的(de)(de)(de)一種(zhong)(zhong)(zhong)油(you)擴(kuo)(kuo)散泵(beng)② 分(fen)餾(liu)式擴(kuo)(kuo)散泵(beng)：這(zhe)種(zhong)(zhong)(zhong)泵(beng)具有(you)分(fen)餾(liu)裝置，使蒸(zheng)(zheng)(zheng)(zheng)汽壓(ya)強較(jiao)低的(de)(de)(de)工(gong)(gong)作液(ye)蒸(zheng)(zheng)(zheng)(zheng)汽進入(ru)高真空(kong)工(gong)(gong)作的(de)(de)(de)噴嘴，而蒸(zheng)(zheng)(zheng)(zheng)汽壓(ya)強較(jiao)高的(de)(de)(de)工(gong)(gong)作液(ye)蒸(zheng)(zheng)(zheng)(zheng)汽進入(ru)低真空(kong)工(gong)(gong)作的(de)(de)(de)噴嘴，它是一種(zhong)(zhong)(zhong)多級油(you)擴(kuo)(kuo)散泵(beng)。

進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)的進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)口(kou)(kou)方(fang)位不對(dui)①進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)的進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)口(kou)(kou)離(li)進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)池(chi)(chi)底和(he)池(chi)(chi)壁間隔(ge)小(xiao)于進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)口(kou)(kou)直徑。若(ruo)是(shi)池(chi)(chi)底有泥(ni)沙等污(wu)物時(shi)，進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)口(kou)(kou)離(li)池(chi)(chi)底的間隔(ge)小(xiao)于直徑的1.5倍時(shi)，會形成抽(chou)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)時(shi)進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)不暢或吸進(jin)(jin)(jin)(jin)泥(ni)沙雜物，阻塞進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)口(kou)(kou)。②進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)的進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)口(kou)(kou)入(ru)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)深度不行(xing)時(shi)，這樣會引起(qi)進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)周(zhou)圍水(shui)(shui)(shui)(shui)(shui)(shui)(shui)面發生漩渦，影響進(jin)(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)，削減出水(shui)(shui)(shui)(shui)(shui)(shui)(shui)量。正確的裝置辦法是(shi)：中小(xiao)型水(shui)(shui)(shui)(shui)(shui)(shui)(shui)真空泵(beng)入(ru)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)深度不得小(xiao)于300～600mm，大(da)型水(shui)(shui)(shui)(shui)(shui)(shui)(shui)真空泵(beng)不得小(xiao)于600～1000mm。

旋(xuan)轉(zhuan)真空(kong)(kong)泵(beng)(beng)又有(you)如下(xia)幾種(zhong)(zhong)形(xing)式：① 油封(feng)式真空(kong)(kong)泵(beng)(beng)：它是(shi)利(li)用油類(lei)密封(feng)各運動部件(jian)之間(jian)的(de)(de)(de)間(jian)隙，減(jian)少有(you)害空(kong)(kong)間(jian)的(de)(de)(de)一種(zhong)(zhong)旋(xuan)轉(zhuan)變(bian)容(rong)真空(kong)(kong)泵(beng)(beng)。這種(zhong)(zhong)泵(beng)(beng)通(tong)常帶有(you)氣鎮裝置，故又稱(cheng)氣鎮式真空(kong)(kong)泵(beng)(beng)。干式螺桿真空(kong)(kong)泵(beng)(beng)：它是(shi)一種(zhong)(zhong)不用油類(lei)（或液(ye)體）密封(feng)的(de)(de)(de)變(bian)容(rong)真空(kong)(kong)泵(beng)(beng)。③液(ye)環式真空(kong)(kong)泵(beng)(beng)：帶有(you)多(duo)葉(xie)片的(de)(de)(de)轉(zhuan)子偏心(xin)裝在泵(beng)(beng)殼內，當它旋(xuan)轉(zhuan)時(shi)，把(ba)液(ye)體（通(tong)常為(wei)水或油）拋向泵(beng)(beng)殼內形(xing)成(cheng)泵(beng)(beng)殼同(tong)心(xin)的(de)(de)(de)環液(ye)，環液(ye)同(tong)轉(zhuan)子葉(xie)片形(xing)成(cheng)了容(rong)積(ji)周期性變(bian)化的(de)(de)(de)幾個小容(rong)積(ji)，故亦稱(cheng)旋(xuan)轉(zhuan)變(bian)容(rong)真空(kong)(kong)泵(beng)(beng)。