為防止真空泵進水，可在抽氣瓶塞上麵增加1個T形管(見圖1), T形管進氣口上接一段橡皮管和1個夾子。抽氣瓶塞下麵接1個單自動活塞，活塞芯下端用線繩固定在1個ge釘ding有you小xiao鐵tie釘ding的de木mu板ban上shang，當dang抽chou氣qi瓶ping進jin水shui時shi如ru接jie觸chu木mu板ban，木mu板ban即ji因yin液ye麵mian浮fu力li將jiang活huo塞sai芯xin向xiang上shang頂ding，使shi抽chou氣qi瓶ping和he真zhen空kong泵beng之zhi間jian正zheng常chang通tong路lu自zi動dong關guan閉bi，真zhen空kong泵beng形xing成cheng盲mang端duan，停ting止zhi向xiang抽chou氣qi瓶ping抽chou氣qi;抽氣瓶內的水液因通路關閉而不能進人真空泵內。關閉開關，停止真空泵運轉。鬆開Txingguanshangdejiazi，rangkongqijinru，ranhousongkaichouqipingxiakoujiazi，shipingneiyetipaichu，huosaixinyinmubanzhonglierxialuo，chouqipingyuzhenkongbengzhijianyouxingchengtonglu，kaiqikaiguan，zhenkongbengzhongxinyunzhuan，chouqiyouzhengchangjinxing。caiquzhezhonggaijinzhuangzhihou，bimianshuiyejinruzhenkongbeng，jieyuelezhenkongbengyou，jianshaolemeicifangshuihehuanyoudemafan。
