DOUBLE-MEMBRANE CENTRAL-FLOW PUMP
The invention relates to a double-membrane central-flow pump controlled by an upper air distribution module with a low-friction pivoting directional valve including a hinged flap for distributing the actuation fluid. The fluid flow outlet and inlet holes in the wet chambers are at different levels inside the projectable section of the chamber. The four ball check valves or similar are disposed in a special arrangement, formed by two suction valves and two delivery valves which are disposed in the wet centre of the pump and which can be accessed from the upper part thereof. The two suction valves are located close to the pump inlet above the shaft, the outlet hole thereof being connected directly to the chamber of the membrane. The two delivery valves are located close to the pump outlet below the shaft and are also connected directly to the chamber of the membrane. The arrangement of the check valves, which can be accessed from the same upper side, allows the valves to be removed from above for maintenance once the air distribution module and the ball covers have been removed, without disconnecting the pump from the fluid line. Moreover, the arrangement of the side covers allows the non-secured membranes to be removed from the sides for maintenance, once the air distribution module and the side covers have been removed, without disconnecting the pump from the fluid line.