It is composed of a spray pump, cooling water tank, nozzle, etc. Its function is to provide necessary cooling and flushing for the cylinder liner, piston (or plunger), in order to improve the service life of the cylinder liner piston (or plunger).

The spray pump is a centrifugal type, which can be driven by a pulley on the shaft head of the input shaft or by an electric motor separately, using water or JH-1 water-based lubricating coolant as the cooling and lubricating medium.

The nozzle is installed on the clamp connecting the intermediate pull rod and piston rod, and can move back and forth with the piston. The nozzle is close to the end face of the piston, and the lubricating coolant can always flush the contact surface between the piston and the cylinder liner, or a fixed spray pipe can be used.