installation and operation instruction造句

• Before steam admission , valve on vacuum hogging extraction line （ the valve is befor hogging pipe of the two stage steam jet ejector ） should be closed ( see also two stages steam jet ejector installation and operation instruction )
  在蒸汽进入之前，抽真空启动管道上的阀门(启动抽汽器前的阀门)应该关闭（请参见相应的两级射汽抽气器安装使用说明书） 。