It alternately pressurizes the inner side of one diaphragm chamber, while simultaneously exhausting the other inner chamber. This causes the diaphragms, which are connected by a common rod, to move endwise. Air pressure is applied over the entire surface of the diaphragm, while grout is discharged from the opposite side. The diaphragm operates under a balanced condition during the discharge stroke, which allows the unit to be operated at discharge heads over 61 meters of water head. Since the diaphragms are connected by a common rod, secured by plates to the center of the diaphragms, one diaphragm performs the discharge stroke, while the other is pulled to perform the suction stroke in the opposite chamber.

The GP150A grout pump is fitted with a heavy duty filter regulator unit which allows for the input air pressure to be adjusted, which in turn adjusts the output pressure of the grout being pumped. As this is a 1:1 pressure ration grout pump the air pressure acting on the inside of the diaphragm will be equal to the grout pressure being pump.

* Please note that maximum flow and maximum pressure cannot be achieved simultaneously and are dependent on distance and materials being pumped.