A rubber pinch valve is a type of control valve. In a pinch valve, the elastomeric sleeve makes contact with the moving fluid and can be made from natural rubber, silicone, or food grade rubber. Its operation is dependent on the pressure differential, which must be precisely measured for proper operation. It is also important that the material of the pinch valve can withstand the application’s temperature and abrasion resistance.
Natural rubber
A natural rubber pinch valve is ideal for bulk materials. The material is versatile and can withstand a wide variety of temperatures. Its abrasion resistance, high rebound resilience, and tensile strength ensure it will last the longest in any application. In addition, this type of valve is ideal for food safety.
The material used to manufacture a pinch valve is important as it can affect the operating conditions. Several types of materials are available, including natural rubber, nitrile, and EPDM. Moreover, the material used to manufacture the valve must withstand the temperature range and pressure differentials of the application.
Natural rubber pinch valves have excellent chemical and biological resistance. They are also ideal for pharmaceutical and food production lines. They have been tested and approved to be used in EX zones and are compatible with abrasive media.
Pneumatic actuator
A pneumatic actuator for a rubber pinch valve is a type of valve that uses air pressure to open or close. These actuators can be fully automatic or semi-automatic. They are often used in throttle valves and other open-close positioning applications. They are fast-acting and quiet, and the pneumatic spring force they encounter when they open or close the valve dampens the sound.
Pneumatic actuators must be sized to match the valve in the system. An undersized actuator can cause erratic stroking and a sudden pressure surge. Oversized actuators can cause damage to internal parts of the valve. Typically, actuators are oversized as a safety feature, but smaller actuators can also be used.
Pneumatic actuators can either be single or double-acting. In either case, the cylinder operates to compress the rubber sleeve. The sleeve/liner is manufactured using a special process. This ensures that the sleeve opens and closes the valve in the same way every time. The elliptical body of the actuator ensures a tight shutoff and a long service life. It also saves energy.
Enclosed-body valve
Closed-body rubber pinch valves are used in a variety of applications. They are ideal for processes that involve entrained solids, like slurries. Because of their linings, they close drop-tight around solids, which makes them safer than other valve types. They also feature a 100% shut-off capability and a full bore for the flow media.
The body material should be lightweight, and the sleeve should be resistant to abrasion. The https://evrproducts.com/products/pinch-valves/ liner material should be abrasion-resistant, as a damaged sleeve will interrupt the flow. Damaged material will also develop memory and protrude into the media stream, which can increase pressure drop and turbulence.
Closed-body rubber pinch valves are available with a variety of seals and sleeve materials. Because the sleeve is the only part of the valve that comes into contact with the media, it is important to choose the appropriate material for the sleeve. A good material for the sleeve is natural rubber, but NBR (nitrile) and silicon may be used.