Aircraft Vacuum Pumps

Aircraft Dry Air Pumps

Dry aircraft vacuum pumps are engine driven by a spline and do not rely on oil to lubricate the vanes of the pump. The carbon vanes of a dry pump are smaller in thickness than those on a wet aircraft pump. The vanes wear as they rub against the inner liner. These aircraft pumps are self-lubricating and do not require an external oil supply.

Aircraft Wet Vacuum Pumps

Wet aircraft pumps siphon air instead of liquid. They can be used for instrumentation and deicer boots. The wet vacuum pump’s vanes are lubricated by aircraft engine oil. The oil is metered by an oil metering collar internally. Oil and air are expelled out of the exhaust port of the wet vacuum pump to an oil/air separator.

Generally, a wet vacuum pump will last longer than a dry air pump. Wet pumps and dry pumps are both subject to failure if the pump is not maintained properly. One of the biggest contributors to aircraft vacuum pump failure is contamination.