Vacuum breaker mechanisms have long been associated with plumbing fixtures to prevent back flow conditions if per chance the water supply pressure becomes negative and the water supply outlet, commonly a hand-held spray spout, is simultaneously submerged in a basin of water. Commonly, the vacuum breaker is in-line with the water supply pipes. However, in-line vacuum breakers are disadvantageous in that their often bulky housing is difficult to conceal and, if they need replacement, require a major plumbing effort. One must break the supply line, remove the housing, replace the housing and reconnect the replacement to the supply lines.
Moreover, vacuum breakers to be effective against anti-siphoning need to be positioned above the sink top commonly referred to as the flood level. With modern plumbing, often the supply lines are concealed below the sink. As such, an extra supply line needs to be detoured above the flood level. Furthermore, the vacuum breaker housing is hard to conceal above the flood level and presents an unsightly appearance in contrast to an often elegant faucet.
What is needed is an anti-siphon breaker valve that can be incorporated into conventional faucet housings so that the air vent is positioned above the flood level and yet be concealed within the faucet. The faucet housing should also have no more openings thereto than a conventional housing. It is also desired to use a conventional valve system that includes supply inlets with valve seats therein and a rigid movable valve member which can selectively cover over the supply inlets to selectively close off or open the supply inlets to an outlet. Furthermore, it is desired to have an easily replaceable vacuum breaker valve.