The pinch valve is a type of valve that is used in a variety of industries. It is often used for applications where media needs to be isolated. It is used in slurries, liquids, and even granular products. It is able to control the flow of these different media.
Pinch valves have three components: the rubber sleeve, the body, and the pinching mechanism. These three components work together to form an effective seal. The rubber sleeve is the only part of the pinch valve that comes in contact with the media. The sleeve is made from a variety of materials, including natural rubber, nitrile, and silicone. The material selected should be able to withstand the temperature and abrasion resistance of the media being handled.
A pinch valve is typically used to prevent the entry of large particulates into a valve seat. This can be beneficial in pharmaceutical, food, and other processes where particle size and cleanliness are essential. Moreover, pinch valves are highly effective in controlling the flow of corrosive media. This is because the sleeve forms a tight shut off around the solids. The sleeve also isolates the flow media from the environment.
The pinch valve is available in a range of sizes and pressure ratings. The pressure rating can be increased by adding metal mesh woven into the rubber sleeve. The pressure rating is not necessarily the pinch valves most important consideration when selecting a pinch valve, though.
The pinch force is the total of the pinch gap and the stroke. The pinch gap is the distance between the opposing pinching surfaces when they are closed. The maximum opening of the pinch valve is usually 50%. It should be noted that this type of valve is not ideal for vacuum applications, as the interruption of the media stream will result in a higher pressure drop.
The pinch valve is ideal for controlling the flow of slurries, liquids, or granular products. It is also useful for throttling applications. Its throttling range is usually between 10 and 95% of the rated flow capacity.
The pinch force is generated by applying a high pressure to the pinch elements. During the closing process, the air nipple pushes down on the rubber sleeve, which forces the pinch element into a closed position. The pressure on the sleeve forces the two pinching bars into the sleeve, which creates a tight shut off.
Pinch valves are designed to be very durable and reliable. They are generally very inexpensive. They are not as popular as other types of valves, and are sometimes less familiar in the process valve world. However, they are widely used in many industrial and medical applications. A pinch valve is a safe and simple valve to use.
When a pinch valve is used for an application, it is best to select a body material that is lightweight, abrasion-resistant, and able to withstand the application temperatures. Common body materials include NBR, EPDM, and food-grade rubber. In addition, it is recommended that pinch valves be sealed with an abrasion-resistant liner. This will reduce the risk of scratching the media and allowing the valve to remain open.