Peristaltic pumps are an easy and affordable way of transferring accurate volumes of fluid.
They use external rotating rollers to generate flow in a tube. The rollers spin in a single, reversible direction around an axis, and during rotation make contact with the outer diameter of the tube. The rollers then press into the flexible tubing, propelling the fluid. As the roller swings away from the tube, the next one makes contact, thus continuing the flow of fluid contained within. The flexible tube becomes compressed at the contact points and this forces the fluid into the direction of the rollers movement.
Compared to other types of pump design, peristaltic pumps offer certain advantages. For example, unlike most other pump systems the fluid only makes contact with the inside of the tube and isn't exposed to any other pump components. This prevents contamination of the fluid and the pump, ensuring that the pump isn't damaged by the fluid and the fluid remains pure and undamaged from the pump operation. It also means the pump can be used without a filter, minimising clean up; and in the event that a tube becomes worn, it can easily be replaced.
Pumping flow rates can be changed by selecting different tube sizes and by operating the pump at different RPM's.