Piston pumps, also called reciprocating pumps, can be powered by an electric motor, steam or a turbine, hydraulic drive mechanism. Piston pumps are capable of differential pressures up to 10,000pounds per square inch (psi).
A piston pump uses the reciprocating motion of a piston rod to move fluid along an axis through a cylinder-shaped chamber. As the piston moves through the cylinder, pressure builds up and forces the fluid through the pump. The fluid flowing through the pump pulsates due to the movement of the piston through the cylinder.
Piston pumps have a wide pressure range, can reach high pressures and the pressure can be controlled without an impact on the rate of flow. Piston pumps have a continuous rate of discharge. Pressure changes and discharge rate have minimal effect on performance. Piston pumps can maneuver viscous fluids, high gas volumes and solids, only if the valves are correctly designed.
Piston pumps cost more per unit to run compared to centrifugal and roller pumps. The mechanical parts are prone to wear, so the maintenance costs can be high. The valves must be resistant to abrasives for large solids to pass through. Piston pumps are heavy due to their large size and the weight of the crankshaft that drives the pump.