No matter what type of piston pumps you are using they all work in the same
way. These pumps can be considered to be one of the most basic pumps that you can use to transfer fluid from one
location to the next.
How Piston Pumps Work
The basic piston pumps consist of two valves and a stuffing box. The inlet valve allows
the water to be sucked into the stuffing box when the piston is driven upward by the motor. The outlet valve is
where the fluid is forced out when the piston is driven down into the stuffing box. The piston is controlled by a
motor that forces the piston to move up and down to create suction, which is what pulls the fluid into the chamber.
All piston pumps, including axial pumps and radial pumps work following this basic theory.
The fundamental difference among these types of pumps is how many pistons there are in the pump and what the pump is being used
for. A perfect example is the axial piston pump, which usually has an odd number of pistons arranged in a
circular pattern inside a cylinder block. In radial piston pumps the pistons are placed in a radial direction
around the drive shaft.
Axial and Radial Piston Pumps
Axial and radial piston pumps are designed differently and this allows them to work perfectly
for the job they are designed for. Before choosing the pumps, you will want to familiarize yourself with the
different characteristics of the different pumps to ensure the pump you eventually pick out will suit your
Axial piston pumps are designed to be able to move the pistons out of the chamber to allow the fluid to
move into the chamber. With these small and compact pumps, this can be done with a spring, whereas other pumps
require the use of a vane pump in order to create the pressure needed. A thing to note about these pumps is the
hydraulic fluid being used to lubricate the pump. The fluid has an operating temperature that it has to operate
within; so many times the fluid has to be cooled down before it can be passed through the pump again. Axial
pumps are known to be very reliable and they are great at regulating flow and pressure. They are much easier and
cheaper to manufacture. One thing you will want to take note is that these pumps are more susceptible to oil
Radial piston pumps are generally also classified as variable displacement pumps which are
capable of generating smooth flow even under extreme pressure. They are also known to very reliable, and in
addition they also run very quietly. The key advantage of this type of pumps is that they can handle high
pressure, which most can handle up to 1000 bar. They are therefore very efficient in applications that involve
high pressure with small flows. They are designed in such a way that the plungers can be turned off one after