Peristaltic Pumps are the simplest possible pumps, with no valves and seals. The fluid contacts only the tubing, eliminating the risk of the pump contaminating the fluid, or the fluid contaminating the pump. Peristaltic pump can operate dry without risk. Backflow and siphoning do not occur. The flow rate depends mainly on the internal diameter of the tube and the speed at which the roller advances. Suction lift capability depends on the restitution power of the tube. The best way to select the tube is to first determined which materials are chemically suitable and then to choose the one that best matches significant pressure, suction or vacuum demands.