The main functions of the vacuum unit equipment are briefly described as follows:

(1) Close the vacuum valve; the unit will cease operation, maintaining a certain vacuum level in the drying system.

(2) The automatic pneumatic safety valve prevents water from the water ring pump system from backflowing into the Roots pump and vacuum drying system in case of an abrupt stop of the unit.

(3) Upon startup of the differential pressure valve assembly, the water ring pump is initiated first. As the differential pressure builds gradually at both ends of the valve, it reaches a certain level, triggering the valve to open automatically. This allows most of the system's gas to flow into the water ring pump through this valve. As the atmosphere gradually flows into the water ring pump via the atmosphere pump, the pressure at both ends of the differential pressure valve decreases, eventually closing the valve. Consequently, the atmosphere pump then commences normal operation. The function of the differential pressure valve is to reduce the pre-evacuation time before the atmosphere pump operates normally.

(4) The check valve on the water level gauge prevents backflow in the water ring pump.