A piston pump is a type of positive displacement pump in which the high pressure seal is coupled with the reciprocating piston. Piston pump can be used to move liquid or compressed gas. They can operate over a wide range of pressures. High pressure operations can be performed without a strong impact on flow rates. The piston pump can also handle viscous media and media containing solid particles. This pump type operates through a piston cup, where the downward stroke causes a pressure difference, and the pump chamber is filled, where the upward stroke forces the pump fluid out for use. Piston pumps are commonly used in high pressure, uniform pressure scenarios and water irrigation or delivery systems. The two main types of piston pumps are lift pumps and forced pumps. Both types can be operated manually or by engine. In a lift pump, the upper stroke of the piston draws water into the lower part of the cylinder through a valve. On the lower stroke, water enters the upper part of the cylinder through a valve arranged in the piston. During the next upstroke, water is discharged from the upper part of the cylinder through the nozzle. In a forced pump, the upper stroke of the piston draws water into the cylinder through the inlet valve. On the next stroke, the water is discharged into the outlet pipe through the outlet valve. An axial piston pump has multiple (usually odd) pistons arranged in a circular array within a housing often referred to as a cylinder block, rotor, or barrel. The cylinder body is driven around its symmetric axis by a monolithic shaft more or less aligned (usually parallel but not always) with the pumped piston.


The above: What matters needing attention when parker piston pump chooses hydraulic fluid?