The piston pump, also called electric reciprocating pump, is divided into single-cylinder and multi-cylinder from the structure, which features high lift. It is suitable for transporting oil emulsions at room temperature without solid particles. It is used in oil field, coal layer water injection, oil injection, oil production; power pump for hydraulic press of ramming press, hydraulic sand-cleaning, and fertilizer plant to deliver ammonia liquid. According to the structure of different materials can also transport high-temperature tar, slime, high-density mortar, high viscosity liquids.

The piston pump is reciprocated by the piston, so that the working volume of the pump chamber is periodically changed to achieve suction and discharge of liquid. It consists of pump cylinder, piston, inlet and outlet valve, inlet and outlet pipes, connecting rod and transmission.

Classification piston pumps are divided into single and double acting type; single, double, multi-cylinder type; lying, standing, inclined type; mobile, manual, pedal, animal type.

Principle During the reciprocating motion of the piston, when the piston moves outwards, the outlet check valve closes under the action of its own weight and pressure difference, and the inlet check door opens under the pressure differential. Pump liquid into the pump chamber. When the piston opens inwards, the pressure in the pump chamber rises, closing the inlet check door, opening the outlet check valve and pushing the liquid into the outlet pipe.