升降機泵站出口的空氣壓力將使泵反轉，會使泵油返到真空室中，空氣也會進入到真空室從而破壞系統的真空。因此需要特殊的閥門把泵和真空室隔開，以防止空氣和泵油進入真空室。
Lifting platform manufacturers to introduce the pump outlet air pressure will pump the pump, pump oil will return to the vacuum chamber, the air will enter into the vacuum chamber to destroy the vacuum system. Therefore, special valves are needed to separate the pump and the vacuum chamber to prevent air and pump oil from entering the vacuum chamber. 

升降機電磁壓差放氣閥是升降平臺真空泵的入口專用閥門，其電源與升降平臺泵的電源聯鎖，放氣閥置于泵入口管道中，其作用為：當泵斷電或控制開關斷開時，電磁閥動作，向泵入口放氣，并且靠大氣壓力自動關閉泵與真空室之間的管道。泵啟動時，電磁閥關閉，泵對閥腔內部抽空，然后閥板靠彈簧壓力打開，使被抽容器與升降平臺泵進氣口接通。
Lifting platform manufacturers to analyze electromagnetic differential pressure release valve lifting platform of the vacuum pump inlet special valve, the power supply and the lifting platform pump power interlock, bleed valve is

arranged in the pump inlet pipe, its function: when the pump power or control switch, solenoid valve action, to the pump inlet gas, and depended on the atmospheric pressure automatically shut down the pipe between the pump and the vacuum chamber. When the pump starts, the electromagnetic valve is closed, the pump is pumped out of the valve cavity, and then the valve plate is opened by the spring pressure, so that the air intake of the pump and the lifting platform pump is communicated with the air inlet of the pump.