A double disc pump includes a stationary main pump housing block that can remain fixed to its supporting frame while all other parts of the pump are removed for servicing. This permits disassembly of the pump without disconnecting the inlet or outlet plumbing and is provided by a pump housing which is vertically divided along parallel horizontal planes into housing segments. An intermediate housing segment is hingedly mounted to the main block segment. A bottom housing segment is hingedly mounted to the intermediate housing segment. These three segments capture all of the internal parts of the pump including the suction and discharge discs and the trunnion seals. The hinged design of the segments allows them to conveniently swing away from other parts of the housing so that access to the internal structures can be accomplished without completely removing each segment.