Categories of exhibits
Air inlet valve
Exhibit no. 797
If the rotary vane vacuum pump stops due to a power failure, it leaves the pump inlet open to the system, which is under vacuum. In that event suck back of oil can occur, causing oil contamination of the vacuum system. Atmospheric pressure acting on the oil surface in the oil box slowly pushes oil into the pump mechanism and towards the inlet side of the pump. To avoid this situation, automatic valves are used to isolate the pump from the vacuum system. Air inlet valves are used to vent rotary pumps to the atmosphere.
The exhibit is Metrovac 1/16” magnetic air inlet valve from the MS902 double-focusing mass spectrometer manufactured by AEI Scientific Apparatus Ltd. in 1969. It was placed on the rotary pump inlet pipeline, between the pump and electromagnetic isolation valve. All three rotary pumps in the MS902 were equipped with this air inlet valve.
