Abstract: An apparatus having an automatic purge valve assembly for draining condensate out of a compressed air storage tank. An air pressure switch, upon the presence of a predetermined atmospheric pressure in the air storage tank, will energize a relay which in turn enables a solenoid to open a purge valve, thus allowing any condensate present in the tank to be automatically drained through and out of an air outlet conduit to which the purge valve is attached. The relay shuts off automatically after only a brief period in order to quickly close the purge valve and thus avoid having a substantial amount of compressed air escape along with the condensate.