Positive Displacement Pump

Positive Displacement Pumps, also known as PD Pumps, are that kind of pumps which displace a known quantity of liquid with each revolution of the pumping elements. They are constant flow machines and are found in a wide range of applications.

How does a Positive Displacement (PD) Pump works?
Positive displacement pumps use gears, lobes, rotary pistons, vanes, and screws to move fluid in a fixed cavity and when liquid exits, the vacuum that is created draws in more fluid. This type of pump forces the fluid from one chamber to another by reducing the volume of the first chamber while increasing the volume of the second. The PD Pump has an increasing cavity on the suction side and a decreasing cavity on the discharge side. Fluid flows into the pump as the cavity on the suction side expands and the fluid flows out of the discharge as the cavity collapses.

Types of Positive Displacement Pump:

• Bladder Pump
• Diaphragm Pump
• Double-diaphragm Pump
• Piston Pumps
• Peristaltic Pump
• Gear Pump
• Rotary Pump
• Rotary Lobe Pump
• Grinder Pump
• Progressive Cavity Pump
• Submersible Pump
• Axial flow pump
• Metering Pump

Applications of Positive Displacement Pump:
Positive displacement pumps are used in a variety of industrial, commercial, and municipal applications such as:

• Construction
• Maritime
• Mining
• Petrochemical
• Pulp and paper
• Power generation industries.
• Petrochemical and hydrocarbon applications
• Chemical-processing
• Liquid delivery
• Biotechnology
• Pharmaceutical
• Food, dairy, and beverage processing

Uses and Features of Positive Displacement Pump:

• PD pump is suitable for liquids with high viscosities and for applications that require high pressures.
  
  
• Important specifications for positive displacement pumps include maximum discharge flow, maximum discharge pressure, inlet size, discharge size and media temperature.
  
  
• Power sources include AC, DC, compressed air, diesel fuel, gasoline, natural gas, water, steam, hydraulic systems and solar energy.
  
  
• Manually powered pumps rely upon hand or foot power.
  
  
• Positive displacement pumps are frequently used in hydraulic systems at pressures ranging up to 5000 psi.
  
  
• The versatility and popularity of PD pump are due to their relatively compact design, high-viscosity performance, continuous flow regardless of differential pressure, and ability to handle high differential pressure.