A peristaltic pump works by pressure and displacement. It is used mainly to pump liquids, yet even with solids, through a hose or tube. Hence no parts of the pump come into a contact with the pumped liquid.
Peristaltic Pumps
6 series from 1 manufacturers
This is the major difference and design advantage compared to other positive displacement pump types.
The simplicity of the hose pump provides a number of advantages. The hose can be made from any of a variety of materials.
More about the working principle
The pump rotor exerts pressure on a set of rollers or shoes which compress the hose. This forms a vacuum drawing fluid into the hose while the next roller or shoe gently pushes the fluid forward. Pump wear is limited virtually to the hose which is quick and inexpensive to replace.