A pinch valve is a type of valve that uses a pinching effect
A pinch valve is a type of valve that uses a pinching effect to obstruct fluid flow. It can be either fully ported or full bore. It uses this effect to control flow of fluids in various applications, such as air, water, and gas. This type of valve is commonly used for pneumatic and hydraulic applications.
Internal
The internal pinch valve is a type of valve used to control the flow of water. It is a mechanical device that includes an actuator dial 12 and a pair of adaptors that enable the valve to be attached to a water supply hose and sprinkler. The adaptors can be either straight or arcuate. In either case, the mechanism of the internal pinch valve is the same.
An internal pinch valve is generally made of rubber or plastic and has a main housing and stem. It can also include a rubber or plastic sleeve. The material of the sleeve is important because it is in contact with the flowing fluid. Various types of materials are used for the sleeve, including silicone, natural rubber, butyl, or PTFE.
External
The internal volume of a pinch valve is determined by its length and inner diameter (ID). Most pinch valves are chosen with an ID of 1.5 mm or less based on the required flow capacity of the application. The internal volume must also be large enough to accommodate the required pressure drop. The choice of material and size of internal and external pinch valves is made by the instrument designer to meet the application requirements.
The electrical energy input to the solenoid is typically high. However, this resource high voltage actuation causes a considerable increase in the armature’s acceleration, which in turn increases the position exponentially. This rapid acceleration and deceleration results in a significant mechanical noise.
Pressure-assisted
A pressure-assisted pinch valve improves valve performance by reducing plastic deformation. It accomplishes this by increasing the contact area between the valve and tubing. It can be customized to meet specific needs and requirements. However, the level of customization is limited by the manufacturing process. A flow-rate versus occlusion relationship can be assessed and optimized, using a computer program to model the valve.
Pressure-assisted pinch valves are available with a wide range of throttling capabilities. The pressure limit is typically 10% to 95% of the nominal flow rate. However, the pressure limit can be increased by injecting outside fluid around the liner. Pinch valve liners are typically made of the same material as rubber hoses. Because the liners are made of the same material, they are often designated with rubber-hose pressure ratings. In the event that the valve is required for higher pressure applications, a larger pressure-assisted pinch valve or a higher Cv valve should be used.
Enclosed-body
The main components of an enclosed-body pinch valve are the sleeve, stem, and main housing. The sleeve material must be lightweight and resistant to deformation and abrasion. Typically, the sleeve is made of EPDM, NBR, natural rubber, silicone, butyl, stainless steel, or a combination of these materials.
The sleeve and the body of the enclosed-body pinch valve are designed for limited-vacuum applications. During a vacuum, the sleeve may collapse due to the suction. Because the sleeve is made of a streamlined flow pattern, it has low sleeve wear.




