134 of metal or stiff plastic the seal 134 has a central opening unnumbered through which a locking pin 136 is inserted to maintain the seal in contact with a plunger 140 the plunger 140 includes an elongated guide shank 142 surrounding the guide shank 142 and biased against the annular flange 112 and the undersurface of plunger seal 134 is a compression spring 144 in operation when the handle 30 is open water entering the cavity 18 will pass through the restricted opening 118 pushing against the diaphragm and passing out see fig1 around the plunger into the hose 100 in order of the preventer 98 to prevent the back flow of water in the hose 100 into the cavity 18 the spring 144 will overcome the water pressure and urge the plunger 140 plunger seal 134 and diaphragm 130 against the sealing disc to seal the same and prevent water from flowing back into the cavity 18 and contaminating the water therein finally there is provided on the faucet 10 a drain fitting collar 150 which is internally threaded the drain means 72 is preferably a metallic brass fitting including a threaded shank end 152 which is threaded into the collar 150 the fitting includes a central body portion 154.