升降机泵站出口的空气压力将使泵反转，会使泵油返到真空室中，空气也会进入到真空室从而破坏系统的真空。因此需要特殊的阀门把泵和真空室隔开，以防止空气和泵油进入真空室。
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. 

升降机电磁压差放气阀是升降平台真空泵的入口专用阀门，其电源与升降平台泵的电源联锁，放气阀置于泵入口管道中，其作用为：当泵断电或控制开关断开时，电磁阀动作，向泵入口放气，并且靠大气压力自动关闭泵与真空室之间的管道。泵启动时，电磁阀关闭，泵对阀腔内部抽空，然后阀板靠弹簧压力打开，使被抽容器与升降平台泵进气口接通。
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.