在真空係統的設計計算中，人們把直接對真空容器進行抽空的真空泵jiaozuozhubeng
，erbaweichilingyigebengdeqianjiyalizailinjieqianjiyaliyixiadezhenkongbengjiaozuoqianjibeng。weileshibeichourongqizhongcongdaqiyalikaishihenkuaidichoudaozhubengnenggoukaishigongzuodeyalidezhenkongbeng，jiaozuoyuchouzhenkongbeng。duiyigezhenkongxitonglaishuo，changchangbaxitongdeqianjibengjianzuoyuchouzhenkongbeng。zhelishuodexuanbeng

，shizhixuanzezhubeng。guanyupeibeng，xiayidejiang，shizhizhengquediweizhubengpipeihaohelideqianjibeng
，guangyieryan，zebaokuoxuanzeqianjibengheyuchoubeng。zhenkongxitongzhongdehexinshebeishizhenkongbeng，zhenkongxitongshejizhongguanjianbuzhoushixuanbengyupeibeng。

xuanbengdejutineirong，jiushiyaoquedingzhubengdeleixing，juedingzhubengdedaxiao。xuanbengdeyuanzeshigongyishangkekao
，jingjishangheli，jishushangxianjin
，xitongshangzuiyou，xingshishangyishu。

確定主泵類型
，首先要考慮的是可行可靠問題
，應該依據真空泵所要達到的極限真空度和工作真空度(選取主泵的極限真空度比真空室的極限真空度稍高)，根gen據ju被bei抽chou氣qi體ti種zhong類lei，每mei種zhong氣qi體ti所suo占zhan比bi例li，以yi及ji氣qi體ti中zhong夾jia雜za灰hui塵chen等deng情qing況kuang
，選xuan擇ze符fu合he工gong藝yi要yao求qiu的de真zhen泵beng空kong。當dang兩liang種zhong以yi上shang的de不bu同tong類lei型xing泵beng都dou適shi合he上shang述shu條tiao件jian時shi，則ze要yao根gen據ju初chu次ci投tou資zi和he日ri常chang維wei護hu費fei用yong等deng經jing濟ji指zhi標biao，選xuan擇ze經jing濟ji上shang合he理li的de真zhen空kong泵beng。然ran後hou，再zai進jin一yi步bu比bi較jiao環huan境jing等deng條tiao件jian，選xuan取qu最zui佳jia的de。為wei此ci，必bi需xu從cong整zheng套tao真zhen空kong係xi統tong出chu發fa，全quan麵mian考kao慮lv，切qie不bu可ke僅jin僅jin作zuo真zhen空kong泵beng的de比bi較jiao就jiu給gei予yu確que定ding。

juedingzhubengdaxiao
，shigenjuzhenkongshizaigongzuoshisuoxuyaodegongzuoyaqiangheshineidezuidapaiqiliang。zhenkongshineidegongzuoyaqiangyidingyaoxuanzaizhubengdezuijiachousuyaqiangfanweizhinei。lingwai，haiyaokaolvzhenkongshidedaxiaohechouqishijian，yinweizaichouqishijianyidingtiaojianxia，ruozhenkongshitijiyueda，zezhubengdechousuyeyueda。