Valve system particularly for apparatus for producing dry compressed air

In a system for producing dry compressed gas, comprising means for supplying compressed gas, means for storing dry compressed gas, liquid separator means, filter means including adsorption filter means and having an inlet, and first passage means connecting said separator means and filter means sequentially between said supply means and said storing means for communication therewith;

• the improvement comprising a pneumatic valve control system in combination with said separator means, said separator means and valve control system comprising housing means providing a cavity, a flexible diaphragm dividing said cavity into an upper chamber and a lower chamber having an inlet and an outlet, said first passage means including means connecting said inlet of said lower chamber with said supply means, baffle means disposed in said lower chamber between said inlet and outlet for separating liquid from said gas, said liquid collecting in said lower chamber, a tap opening in the bottom of said lower chamber, valve means associated with said tap opening and movable between an open position for opening said tap opening and a closed position for closing said tap opening, means connecting said valve means with said diaphragm for movement by said diaphragm between open and closed position, a suction ejection nozzle having a suction chamber in which a reduced pressure is produced by flow of gas through said nozzle, said first passage means further including means connecting said suction ejection nozzle between said outlet of said lower chamber and said inlet of said filter means in communication therewith so that said gas flowing through said suction ejection nozzle in flowing from said separator means to said filter means produces a reduced pressure in said suction chamber, second passage means connecting said suction chamber of said ejection nozzle with said upper chamber in communication therewith to provide a pressure differential on said diaphragm to deflect said diaphragm when there is a flow of said gas at a predetermined rate through said nozzle and thereby move said valve means to closed position, said valve means being biased to open position when said diaphragm is not thus deflected, whereby said valve means is maintained in closed position by said diaphragm to close said tap opening when said gas is supplied by said supply means and flows through said separator means, valve control system and filter means to said storing means, and is moved to open position, when said gas is not so supplied, to open said tap opening to drain said collected liquid from said lower chamber and to permit back flow of said gas from said storing means through said filter means to regenerate said adsorption filter means.