Abstract: Module control block assemblies are clamped in a bank to individually control to handpieces drive air and air and water coolants and also supply drive air pressure to a gauge through an oversize aligned bore in blocks of the assemblies through which extends a tie rod clamping the assemblies together. The blocks have supply passages therethrough for the above fluids, and covers for the blocks have diaphragm chambers and passages therealong to control flow of the fluids to outlets in the block. Water coolant control valves are mounted on the covers, and are supplied with control air and water coolant from branch passages in the blocks leading to passages through diaphragms and the covers.