As the name implies, a pinch valve consists of a rubber sleeve that gets pinched (squeezed) between two mechanical pinch bars, or squeezed close with air or fluids. This rubber sleeve is housed inside a frame or body, so that the mechanism can be built around it. Different housings and end covers/flange materials such as cast-iron, steel, aluminium, plastics and stainless steel can also be used.
With the Rhinoflex Pinch valves, the Rubber Sleeves are the only wetted part exposed to abrasive/corrosive media flow. Pinch valves are also used for slurries or processes with entrained solids, because the flexible rubber sleeve closes drop-tight around solids. This avoids entrapment by the seat or in crevices, which would happen if using globe, diaphragm, butterfly, gate or ball valves.
When the sleeves wear out, they can be easily replaced on site, resetting the service life clock of the valve. A quick sleeve replacement essentially gives the user, a new valve at a fraction of the cost. There is no need to replace the entire valve assembly. The most important benefits of using pinch valves are the full bore for the flow media, and 100% tight shut off – even on solids such as granules, powders, pellets, and all kind of slurries and aggressive products.
Traditional valves could fail when in contact with aggressive products, due to body seat or the gate/piston wearing out too quickly. Air-operated pinch valves work with less wear of the elastic rubber hose because the kinetic energy of the solids are absorbed through the high elasticity of the rubber that also helps to resist abrasion.