Griswold Pump Company”s H Series Self-Priming Centrifugal Pumps are designed for use in unloading barges, railcars and tank trucks, with the goal to remove as much of a shipment’s “heel” as possible. The tank heel refers to the amount of liquid remaining in each tank after lowering to the greatest extent possible by use of the existing transfer equipment. The pumps are able to satisfy the needs of transport unloading due to their self-priming design. As fluid levels drop, the pump evacuates air as it begins to enter the suction line, improving transport-unloading efficiency. These pumps are available in three, five, 7.5, 10, 15, and 20-horsepower models with heads up to 270 feet and flowrates to 325 GPM. Other efficiency-optimizing features of the pumps include a closed impeller, a mechanical shaft seal, stationary seal face and rotating seal face, a heavy-duty case of cast iron, and a heavy-duty rigid bracket that maintains perfect alignment between the pump and motor.