A peristaltic pump is a type of positive displacement pump used for pumping a variety of fluids. The fluid is contained within a flexible tube fitted inside a circular pump casing. As the rotor turns, the part of the tube under compression is pinched closed thus forcing the fluid to be pumped to move through the tube.
Additionally, as the tube opens to its natural state after the passing of the cam fluid flow is induced to the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract. The body of fluid is then transported, at ambient pressure, toward the pump outlet.
Peristaltic pumps may run continuously, or they may be indexed through partial revolutions to deliver smaller amounts of fluid.
Peristaltic pumps are used in a wide variety of industrial applications. Their unique design makes them especially suited to pumping abrasivesand viscous fluids.
The pumped fluid contacts only the inside surface of the tubing thereby negating concern for other valves, O-rings or seals that might be incompatible with fluid being pumped. Therefore, only the composition of the tubing that the pumped medium travels through is considered for chemical compatibility.
The tubing needs to beelastomeric to maintain the circular cross section after millions of cycles of squeezing in the pump. This requirement eliminates a variety of non-elastomeric polymers that have compatibility with a wide range of chemicals. Popular elastomer for pump tubing issilicone which is common with water-based fluids, such as in bio-pharmaindustry.