The core functionality of a pinch valve is a flexible flow path element that is compressed by an external plunger or pinch block. Most pinch valves employed in these industries are actuated using a solenoid, although some manual hand-actuated pinch valves exist, and they operate like a clamp.
External pinch valves are characterised by tubing that can be easily replaced; internal pinch valves are sealed and maintenance free. The choice of valve for a scientific or medical instrument application is dependent upon several factors. Consideration should be given to the internal volume, carryover volume, maintenance, cycle life, and materials. These factors are discussed in greater detail below.
Read the full article in DPA's December issue