PINCH VALVE

 

 A pinch valve is a full bore or fully ported type of control valve which uses a pinching effect to obstruct fluid flow. There are a few types of pinch valves based upon application. Pinch valves used for fluids usually employ a device that directly contacts process tubing. Forcing the tubing together will create a seal that is equivalent to the tubing's permeability. Pinch valves are typically used in applications where the media needs to be completely isolated from any internal valve parts or entrapments. They are commonly applied to medical instruments, clinical or chemical analyzers, and a wide range of laboratory equipment. Major components of a pinch valve consists of body and a sleeve. The sleeve will contain the flow media and isolate it from the environment hence reducing contamination to the environment. Generally used for slurries or processes with entrained solids, because the flexible rubber sleeve allows the valve to close drop tight around solids—solids that would typically be trapped by the seat or stuck in crevices in globe, diaphragm, butterfly, gate, or ball valves. The sleeve material can be selected upon the corrosiveness and abrasiveness of the flow media, a suitable synthetic polymer can be chosen. A pinch valve may be the best type of valve for flow control application if the operation temperature is within the limit of the polymer.Untitled 8