Image Number 3 for United States Patent #5176165.
An air gap apparatus particularly adapted for use in reverse osmosis (RO) units in which reject water must be carried off to a drain line. The apparatus is adapted for incorporation in an RO unit as original equipment or for addition later as an after market item. It provides air gap protection against backsiphoning, and also includes a deflector wall and supplemental opening for shunting to atmosphere any high velocity backflow from the drainage line. Various forms of check valves are disclosed for use with the air gap apparatus to provide further protection against contamination of the potable water system by backflows, the check valves being adapted in certain embodiments for connecting together conduit sections within which the check valves have been installed. Also, a compact and inexpensive form of trap is disclosed for use in systems which do not include a conventional drain trap.