一般采用分(fen)凝法(fa)，從空氣(qi)裝置(zhi)中提取粗(cu)氦(hai)(hai)(hai)(hai)、混合(he)氣(qi)，由粗(cu)氦(hai)(hai)(hai)(hai)、混合(he)氣(qi)制(zhi)純氦(hai)(hai)(hai)(hai)，經分(fen)離及純化(hua)，制(zhi)得99.99%的(de)(de)純氦(hai)(hai)(hai)(hai)氣(qi)。液(ye)態(tai)氦(hai)(hai)(hai)(hai)在溫(wen)度下降至2.18K時(shi)，其比熱容、表(biao)面張(zhang)力、壓縮性都是反(fan)常的(de)(de)。這種異常的(de)(de)液(ye)體(ti)叫做(zuo)液(ye)氦(hai)(hai)(hai)(hai)Ⅱ，正常的(de)(de)液(ye)態(tai)氦(hai)(hai)(hai)(hai)叫做(zuo)液(ye)氦(hai)(hai)(hai)(hai)Ⅰ。氦(hai)(hai)(hai)(hai)氣(qi)可作為火箭液(ye)體(ti)燃(ran)料的(de)(de)壓送劑和增(zeng)壓劑，大量用于(yu)宇宙飛船和超音速飛機上。氦(hai)(hai)(hai)(hai)氣(qi)有優良的(de)(de)滲透性，用于(yu)核(he)反(fan)應(ying)堆的(de)(de)冷卻(que)，氦(hai)(hai)(hai)(hai)氣(qi)的(de)(de)價格，火箭和核(he)反(fan)應(ying)堆的(de)(de)一些管道(dao)及電(dian)子和電(dian)氣(qi)裝置(zhi)等的(de)(de)檢漏。

液氦的導(dao)熱率異乎尋(xun)常地高(gao)，其(qi)內部(bu)不(bu)可(ke)(ke)能(neng)出現溫差，因而(er)內部(bu)不(bu)可(ke)(ke)能(neng)汽化(hua)，即不(bu)能(neng)沸騰(teng)。當利用(yong)抽氣(qi)方(fang)法減(jian)低蒸氣(qi)壓時，開始階(jie)段出現激烈的沸騰(teng)，溫度降低至λ點以下(xia)時，沸騰(teng)突然(ran)停止，液面平靜如鏡，汽化(hua)只(zhi)發生在液面。充了氮(dan)氣(qi)的輪胎還可(ke)(ke)以防止輪胎自然(ran)氧化(hua)和龜(gui)裂，因為純凈的氮(dan)氣(qi)不(bu)像空氣(qi)那樣含有包括(kuo)水在內的多種(zhong)成分，因此對橡膠的腐蝕性小，能(neng)夠(gou)延(yan)長輪胎的使用(yong)壽命。氦氣(qi)廣泛應用(yong)于、科研、石化(hua)、制冷、、半導(dao)體、管道檢漏(lou)、超導(dao)實驗、金屬制造、深海潛(qian)水、高(gao)精度焊接、光電子產品生產等。

潛(qian)(qian)水(shui)時，通過結(jie)合(he)使用(yong)(yong)(yong)(yong)(yong)(yong)(yong)氧氣(qi)和氦(hai)(hai)氣(qi)，可有效消除氮，減小深處呼吸阻力(li)并(bing)縮短減壓停(ting)頓時間。氦(hai)(hai)氧混合(he)氣(qi)能使潛(qian)(qian)水(shui)者在(zai)(zai)水(shui)中(zhong)(zhong)更(geng)深處停(ting)留更(geng)長時間。潛(qian)(qian)水(shui)越深，氦(hai)(hai)氣(qi)濃度越高，潛(qian)(qian)水(shui)者便(bian)能下潛(qian)(qian)更(geng)深并(bing)實現更(geng)長的焊(han)接時間。氦(hai)(hai)在(zai)(zai)常溫常壓下為(wei)無(wu)色無(wu)臭無(wu)味(wei)***的惰(duo)性(xing)氣(qi)體(ti)。不(bu)燃燒。微溶于(yu)水(shui)和。氦(hai)(hai)是僅次于(yu)氫的輕(qing)氣(qi)體(ti)，易(yi)擴散和滲透，化學(xue)性(xing)質穩(wen)定，因(yin)此，常用(yong)(yong)(yong)(yong)(yong)(yong)(yong)它作(zuo)探漏氣(qi)體(ti)。氦(hai)(hai)氣(qi)在(zai)(zai)科學(xue)實驗、臨床和工業生產上都(dou)有著非常廣(guang)泛(fan)的用(yong)(yong)(yong)(yong)(yong)(yong)(yong)途。從大型(xing)強子對撞(zhuang)機(ji)(ji)到點(dian)焊(han)機(ji)(ji)（一種焊(han)接機(ji)(ji)器），液氦(hai)(hai)被廣(guang)泛(fan)地用(yong)(yong)(yong)(yong)(yong)(yong)(yong)來冷卻設(she)備，因(yin)為(wei)它既(ji)方便(bian)又有效。另(ling)外，液氦(hai)(hai)的用(yong)(yong)(yong)(yong)(yong)(yong)(yong)途是用(yong)(yong)(yong)(yong)(yong)(yong)(yong)在(zai)(zai)磁共(gong)振成(cheng)像(xiang)(xiang)設(she)備中(zhong)(zhong)。磁共(gong)振成(cheng)像(xiang)(xiang)可以應用(yong)(yong)(yong)(yong)(yong)(yong)(yong)于(yu)全身各系(xi)統的成(cheng)像(xiang)(xiang)診斷，而其設(she)備中(zhong)(zhong)的超導磁體(ti)需要用(yong)(yong)(yong)(yong)(yong)(yong)(yong)液氦(hai)(hai)來冷卻到接近零度。這種醫學(xue)設(she)備是用(yong)(yong)(yong)(yong)(yong)(yong)(yong)氦(hai)(hai)大戶，用(yong)(yong)(yong)(yong)(yong)(yong)(yong)氦(hai)(hai)量大約(yue)占全世(shi)界用(yong)(yong)(yong)(yong)(yong)(yong)(yong)氦(hai)(hai)量的1/3。