Plunger pumps / piston pumps are suitable for high pressure & high flow rates
As the dynamic high-pressure seal of the plunger pump is not attached to the moving plunger body, but to the housing of the pump, complex sealing systems are possible. The sealing system design is critical, and these designs have countless variations. Thus, a plunger pump can be adapted to many various fluids and environments. The pump’s housing and inner parts can be produced out of nearly any material. By the correct material choice, it is possible to pump abrasive, corrosive, hot, cold, viscous, toxic and flammable fluids – even under highest pressures. In this case, elaborate leakage monitoring and almost any barrier fluids can be used. If a fluid has a high vapour pressure, a plunger pump can also pump this by increasing the charge pressure of the plunger pump. Even sterilizable designs of plunger pumps are possible for any pressure level. For potentially explosive environments, it is possible to construct plunger pumps which are explosion proof.
Because the oscillating plungers are powered by force by a crankshaft, it is possible to overcome the highest flow resistance. That is why a plunger pump can also be used in processes with highest pressures, if the driving motor/power unit is strong enough.
The crankshaft, which powers the plunger, is usually rotated by a slower rotational speed than that of common prime movers. This is why most of the plunger pumps have an integrated gear reduction. Only very small pumps up to 45kw are powered by external v-belt-drives. For very large pumps tend to have no integrated gear reductions but use an external gearbox between the pump and its drive.
Because plunger pumps belong to the oscillating positive displacement pumps, the flow rate for a given pump depends only on the rotational speed of the pump’s crankshaft. The characteristic line of the delivery rate is nearly linear and directly proportional to the crankshaft speed. As a result, dosing tasks can be performed just as well as speed-dependent pressure control – up to many thousand bar operating pressure.
Due to the design, plunger pumps work with efficiencies of more than 90%! This makes their use interesting wherever energy saveing is a priority. The high energy density – or small size – of plunger pumps fascilitates their installation enormously.
Due to its many advantages, a plunger pump is often an economically viable alternative to previously used solutions.