The present invention is a central flow double diaphragm pump controlled by an operating fluid distribution module on the topside. A pivoting sealing member with a protruding wing pivots on the low friction seal of the operating fluid distribution module. The pumped fluid chambers' inlet and outlet ports are positioned at different levels within the projected section of each chamber. The four check valves, for example, but not necessarily, ball valves, are arranged in a special configuration. All four check valves, two suction check valves and two discharge check valves, are located in the centre of the pump's wetted body and are accessible from the topside of the wetted body. The two suction check valves are located close to the pump inlet, above the shaft, and the valves' outlets connect immediately into the diaphragm chambers. The two discharge check valves are located close to the pump outlet, below the shaft, and the valves' inlets connect immediately from the diaphragm chambers. The arrangement of the
