Expello Valves Protect Air Compressors

The compressed air system in a heavy-duty truck begins with the air compressor.  Located in the engine compartment the air compressor relies on the truck for filtered air, power, and lubrication.  When the truck is running the compressor is running so a governor is utilized to allow the compressor to cut in and cut out as necessary.


Because the air compressor uses engine oil for lubrication oil vapor is created as the air is compressed.  This vapor along water vapor will pass to the air dryer.  In high use situations the water vapor can saturate the desiccant bed.  The oil vapor will foul the desiccant bed allowing more oil and water to pass to the wet tank.  If this sludgy mixture is not drained from the tank it will cause problems for every air actuated component on the truck.


If enough water builds up in the system, the compressor will cycle more often than necessary as it tries to keep the system supplied with the required amount of air.  This will lead to premature failure of the compressor.  The best way to protect an air compressor is to drain the air tanks regularly.  The best way to ensure that tanks are drained regularly is to install an Expello automatic drain valve to remove the oil and water from the wet tank.  Purging the contents of the wet tank every 5 minutes that vehicle is keyed on ensures that air compressor won’t over cycle due to water build up in the system.