How does an air dryer know to purge?

How does an air dryer know to purge?

The purge cycle of the air dryer begins when the governor causes the compressor to unload (stop compressing air). During compressor unload, the line connecting the governor unloader port to the AD-9 air dryer end cover control port is pressurized. The air pressure causes the air dryer purge valve to open.

How often should a air dryer purge?

Air Tanks and Purge Valves A second simple step toward keeping the air system moisture-free in winter is manually draining the air tanks – periodically, based on the truck’s air usage. Up to once a month for vehicles with high air demand or every three months for a typical line haul truck is recommended.

What do short purge cycles indicate?

Purge cycle is too short (five seconds or less) – pressure-controlled check valve is OK, no leak in governor control line. Regeneration valve not allowing enough air to come back into cartridge. Air dryer purges – but no regeneration, no check valve between air dryer and supply tank, and purge valve has not closed.

Why do you need to drain the air tank regularly?

Why do you need to drain air tanks regularly? Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.

Why does my air dryer Purg every 30 seconds?

Your intuition is probably right. I think it would be the unloaders. When the system reaches 120psi the governor allows system air to the air dryer to signal the purge and allows air to the unloaders. The unloaders will just hold the check valves off their seat in the compressor head to stop the air from being pushed out of the compressor.

What causes air dryer to stop compressing air?

Constant exhaust of air at air dryer purge valve exhaust when air dryer is in Charge mode. Compressor fails to unload (stop compressing air) and air dryer purge exhaust makes “sputtering” or “popping” sound Purge control line connected to reservoir or exhaust port of governor. It must be connected to an unloader port on the governor.

What causes air dryer to sputter when in charge mode?

Constant exhaust of air at air dryer purge valve exhaust when air dryer is in Charge mode. Compressor fails to unload (stop compressing air) and air dryer purge exhaust makes “sputtering” or “popping” sound Purge control line connected to reservoir or exhaust port of governor.

What causes air compressor to stop building air?

to stop the compressor from building air and also causes the air dryer to purge. As the service reservoir air pressure drops to the “cut-in” setting of the governor, the governor returns the compressor back to building air and the air dryer to air drying mode. As the atmospheric air is compressed, all the water