Does my Wabco dryer need a purge tank?

I cant be sure you name all parts right, but purge tank, is really dryer regeneration tank. It is small, about a gallon, and when compressor cuts off air from this tank runs in reverce direction from air dryer cartridge, blowing out oil/water emulsion throught the regeneration passage (down to ground).

 

That little tank would be an aid to your dryer and improve the dryers performance by:
Collecting water and oil that would normally be cycled through the dryer.
Providing air volume at the dryer for the purge cycle.
The addition of the tank would extend dryer service intervals and help prevent dryer freeze up in winter weather.
The tank should be drained daily for maximum efficiency.
The tank isn't necessary, but a good addition if regularly tended to.

 

Modern air dryers drain purge tank automaticly every time compressor cuts off. simple idea but saves cartridge.

New electronic air dryers are smart and calculate cartrige use. but EAPUs are expencive toys and now they are rare