A rubber pinch valve (also commonly known as a pinch cock, soft-seated valve, bladder valve or rubber hose valve) controls the flow of fluids and provides a leak-proof seal when closed. These are simple to install, require minimal maintenance and offer a long service life.
Pinch valves are available in different designs, and can be operated manually or with an electric motor actuator. They are also available in a range of sizes and are used for many applications in the industry.
Air operated pinch valves – 100% tight shut off and full bore
The key advantage of air-operated pinch valves over ball, piston or gate valves is that they can be operated with compressed air and don’t need any additional actuator. The only thing the pinch valve needs to close is a pressure difference of up to 2 bar, which is supplied into the body of the valve, compressing the specially manufactured rubber sleeve that fully collapses and closes. This ensures a complete and 100% tight shut off for all granulate, powder, pellets, chippings, fibres, slivers or any kind of slurries.
A special lipped fold pattern of the sleeve makes it easier to seal even large solids in the valve, without allowing the flow media to escape through the sleeve. This makes them perfect for applications with abrasive, corrosive or fibrous solids such as granulates, powders, pellets, chips, fibres, slivers, slurries and aggressive products.
Liner material – abrasion-resistance and corrosion resistance
The liner of a pinch valve is made from a flexible, elastomer material that can withstand the flow media’s kinetic energy. Depending on the media, this can be natural or synthetic rubbers, plastics or any other suitable synthetic polymer, ensuring a high resistance to corrosion and abrasion in the medium.
Choosing the right pinch valve is an important consideration for any industrial application, as it needs to be capable of handling abrasive and corrosive fluids with high concentrations of solids. This is particularly the case when using heavy-duty pinch valves with a long operating time in open and close mode, as well as proportional control, such as in mineral processing, cement and construction industries, iron and steel production, metallurgy or foundries.
When choosing a pinch valve, you should also consider the maximum fluid flow capacity, and the minimum wall-thickness of the tube that is needed for operation. In addition, the throttling range of the valve is critical to determine how the pinch valve will behave in the event of a failure.
Pinch valves are ideal for the handling of slurries and liquids that contain suspended solids because the flexible rubber sleeve that closes droptight around solids can avoid entrapment by the seat or in crevices, which could occur with globe, diaphragm, butterfly or ball valves. Moreover, the pinch valve offers a more secure shut-off than conventional types of valves such as ball, piston and gate valves, due to its low wear rate.
A pinch valve is the simplest and most cost-effective type of valve, which can be easily installed and maintained. It is also an excellent choice for systems that convey large amounts of solids pneumatically.