A fluid module for a fluid control apparatus which has an internal fluid operated diaphragm which will permit the manifolding of several modules together. Each of the modules is of the same configuration and is interconnected to a common main fluid supply source. The modular units are plugged together using couplings with the main fluid source piped only to one device with an internal fluid passage delivering the fluid to all of the modular units. The modular units can be connected in a series or parallel combination with respect to signalling fluids. The modular units eliminate the cost of interconnecting different units at a variety of locations with different couplings as well as independently supplying each unit with a supply fluid.