Connect the vacuum pump to the compound pressure gauge; open the compound pressure gauge and vacuum pump to vacuum the indoor unit and connecting pipe.
将真空泵连于复合压力表，打开复合压力表和真空泵对室内机和连接管抽真空。
2
The addendum coefficient is an important parameter in the designing the gear, and to affect the discharge characteristic of compound gear pump.
齿顶高系数是设计齿轮时的重要几何参数，也是影响复合齿轮泵流量特性的重要参数之一。
3
Vacuum pump is a vacuum distillation of the core of the compounds according to the boiling point to be distilled and compound use, choose the appropriate pump.