Peristaltic pumps are positive displacement pumps used to pump a variety of fluids. The fluid is contained within a flexible tube mounted within an annular pump housing (although a linear peristaltic pump has been manufactured). A plurality of "rollers," "shoes," "wipers," or "bumps" rotors attached to the periphery of the rotor compress the flexible tube. As the rotor rotates, the compressed tube portion is clamped (or "blocked"), forcing fluid through the tube. In addition, fluid flow is introduced into the pump as the tube is opened to its natural state ("recovered" or "elastic") after the cam passes. This process is called peristaltic and is used in many biological systems such as the gastrointestinal tract. Normally, there will be two or more rollers or wipers that block the tube and trap a stream of fluid between them. The body of the fluid is then delivered to the pump outlet under ambient pressure. The peristaltic pump can run continuously or can be indexed by partial rotation to deliver a smaller amount of fluid.
Peristaltic pumps are often used to pump clean/sterile or aggressive fluids without exposing these fluids to the contaminants of exposed pump components. Some common applications include pumping intravenous fluids through infusion devices, apheresis components, corrosive chemicals, high-solids slurries, and other materials where product isolation from the environment and product environment are critical. Since the pump does not cause significant hemolysis, it is also used for bypass surgery in heart-lung machine circulation.
Peristaltic pumps are also used in various industrial applications. Its unique design makes it particularly suitable for pumping abrasives and viscous fluids.