A double diaphragm pump is provided. The pump includes an inlet manifold, an outlet manifold, an air valve housing, first and second diaphragm housings, and a collar. The inlet manifold has at least one passageway configured to direct fluid from an inlet port on the inlet manifold. The outlet manifold has at least one passageway configured to direct fluid to an outlet port on the outlet manifold. Each of the housings is in selective fluid communication with the inlet and outlet manifolds. The collar is configured to be rotatably attached to the inlet manifold and the pump.