Working Principle of Plunger Pump

Quintuplex plunger pump, model EG5-1000

A plunger pump, also known as a reciprocating pump, operates based on a straightforward yet effective principle. Here's a breakdown of how a plunger pump works:

1. **Mechanism**: The plunger pump consists of a piston or plunger that moves back and forth inside a cylindrical chamber. The plunger is typically connected to a crankshaft or some form of reciprocating mechanism.

2. **Suction Stroke**:

  - During the suction stroke, the plunger moves away from the pump chamber, creating a low-pressure area.

  - This low pressure causes the inlet valve (often a one-way valve or check valve) to open, allowing fluid to enter the pump chamber from the reservoir or source.

3. **Compression Stroke**:

  - As the plunger reverses direction and moves towards the pump chamber, the inlet valve closes to prevent backflow.

  - The fluid is then compressed inside the chamber by the reducing volume created by the plunger's movement.

4. **Discharge Stroke**:

  - At the peak of the compression stroke, the outlet valve (another one-way valve) opens due to the pressure build-up.

  - This allows the high-pressure fluid to be pushed out of the pump chamber and into the discharge line or system.

5. **Repeat**:

  - The cycle repeats with the plunger moving back and forth, drawing in fluid during the suction stroke and forcing it out under pressure during the discharge stroke.