Abstract: A valve assembly is provided which is in two units, each of which assumes a normally closed position when the units are separated and is opened when the units are mated. One unit includes a valve body with a transverse wall having an opening therethrough which is normally closed by a diaphragm which is provided with openings through it outside of the location where it engages the wall. The other valve unit includes a valve body having a spring-biased plunger which at its end has an integral pin engageable with the diaphragm when the units are advanced toward each other for deflecting the diaphragm away from the opening in the transverse wall, and an additional projecting portion for engaging the transverse wall to cause the plunger to be deflected away from the valve seat, thereby to open up communication through both valves.