A peristaltic pump is a positive displacement pump, which is based on alternating compression and relaxation of a hose or tube, similar to the way a human throat or intestines work. A rotating shoe or roller passes along the length of the tube, compressing it and creating a seal, causing a strong vacuum and drawing in the product to the pump. As the product reaches the end of the tube, it is 'pushed' out of the discharge port.
Smaller tube-type models have their tubes installed in a rotor assembly alongside the cased mechanism and controls. Industrial type models house the hose in a cast iron casing with the hose half covered with a lubricant bath to reduce the friction on the surface from the rotor mechanism and to-regulate the temperature of the pump. The rotor is connected to a drive assembly, motor, gear box and control unit.