Select Page

What is a Positive Displacement Pump?

Dec 29, 2017 | Glossary

Positive displacement pumps are “constant flow” pumps.

Despite pressure in the discharge, positive displacement pumps will not adjust their flow rate. To prevent pressures exceeding that of safe levels within the system, relief valves must be installed. In the event of a blockage in the discharge piping, the pressure can safely be relieved before damage occurs. Without a relief valve, the pump will continue to increase the pressure until the pressure is “relieved”- either by a piping failure, cracked fluid end, or a broken coupler or driveshaft. These failures are often catastrophic, endangering personnel and surrounding equipment systems.

What Are Positive Displacement Pumps Used For?

  • High Pressure, Low Flow
  • High Viscosity
  • Mud or Abrasives
  • Precise Flow

Types of Positive Displacement Pumps

Reciprocating Pump

Rotary Pump

  • Progressive Cavity
  • Screw Pump
  • Gear Pump
  • Lobe Pump
  • Peristaltic Pump
  • Swash Plate
  • Rotary Vane

Power Zone's In-Stock Equipment

All Inventory

1,000' of industrial equipment items!


1,000's of In-Stock Industrial Pumps ready to go or for rebuilding.


In-Stock Engines for rebuilding or direct purchasing.

Power Transmission

Gear boxes and more!