Positive Displacement Pumps
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Positive Displacement Pumps

Positive displacement pumps allow a wide range of liquids, slurries and foams to be transported without product degradation. Types of positive-displacement pumps are reciprocating, metering, and rotary pumps. Positive displacement pumps can be further classified as either rotary type (i.e. rotary vane pump) or reciprocating type (i.e. diaphragm pump or piston/plunger pump). Both rotary type and reciprocating type pumps operate very similar with slight differences between the two:

  • In all rotary designs, the chamber is created progressively through rotation of the drive shaft. There may be one or more chambers opened per revolution of the drive shaft. The chambers are sealed off from suction by close clearance between the rotor and the housing, or by close clearance between intermeshing rotors. Rotation of the shaft moves the chamber along the bore or housing towards discharge. The chamber is displaced to discharge rotation. The release to discharge progresses with rotation as the volume is expelled so that the flow is typically pulsation free.
  • In all reciprocating designs, there are check valves on the suction and discharge. Fluid flows through the suction valve and into the chamber as the plunger, piston, or diaphragm recedes. At the end of the stroke, the chamber is at its maximum size. The suction valve closes, the plunger moves forward into the chamber, forcing the fluid out the discharge valve. The flow from each chamber is a pulse flow. If the pump has several chambers, they are timed to have sequential pulses to minimize the overall pulsation.

The knowledge of our team combined with the world’s leading manufacturers can provide you with an innovative and cost effective solution.

Their are many different types of rotary or reciprocating type positive displacement pumps. Here is a comparison of each of the following below.

  • Air Operated Pump
  • Gear Pump
  • Hose Pump
  • Metering Pump
  • Piston pump
  • Progressing Cavity Pump
  • Rotary Lobe Pump
  • Rotary Vane Pump
  • Sanitary Pump
  • Sealed
  • Sealless
  • Rotary gear pump
  • Screw pump
  • Regenerative (peripheral) Pump
  • Peristaltic

Please click here or the image below for some descriptive diagrams of how each of these positive displacement pumps differs and some example applications of each.

Please visit some of our supplier websites to see our complete product offering:

Air OperatedGearHoseMeteringPistonProgressive CavityRotary LobeRotary VaneSanitarySealedSealless
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