Positive Displacement Pumps

Types of positive displacement pump:

• Diaphragm Pumps
  • These pumps operate with a minimum of two separate valves, much like a heart or a diaphragm; as one chamber opens, another chamber reciprocates by closing and vice versa. These pumps can have one diaphragm or have multiple, such as an AODD (air-operated double-diaphragm pump).

• Gear / Rotary Vane Pumps
  • These pumps utilize gears or other methods of rotation to transfer the fluids where they need to go. There are a few different kinds of rotary or gear pumps, depending on the size or shape of the mechanism. These kinds of pumps require priming, meaning that they should not operate without already containing liquids.
• Reciprocating Pumps
  • While similar to centrifugal pumps, reciprocating pumps use a rotating piston within the sealed cylinder. They are best suited to provide low-volume, high-pressure output.
• Peristaltic Hose Pumps
  • These kinds of pumps have liquid piped in a half-circle through flexible tubing. Pressure then pushes the fluid from one end to another via a ‘roller’ or ‘wiper.’ They are often used to transport fluids without exposing them to gasses or contaminants.
• Progressive Cavity / Helical Rotor Pumps
  • These pumps utilize a rotor designed to maneuver fluids through a container with a corkscrew rotor. The cavities within this pump are sealed off from each other, allowing for more efficient pumping, even when dealing with higher pressures.
• Eccentric Disc Pumps
  • These pumps operate similarly to both peristaltic hose & centrifugal pumps. Along the shaft, there are a pair of discs, one stationary and one rotating as the shaft moves in a small circle. The rotating disc acts like the foot on a peristaltic hose pump and pushes fluid through the stationary disc and out of the pump.