Where powders and granulars are being handled there is the risk that this type of
media will choke or block valves, for example in storage hoppers and tanks. One way to eliminate these problems is to specify pinch valves, which by design, are unlikely to become caked or clogged by media containing powders, granules or other similar solids. Milton Roy UK offers a wide range of competitively priced automatic pinch valves which provide the important advantages of providing a complete seal, without the need for glands, whilst also ensuring a full flow within the process line. Also, the problems of a pressure drop occurring are avoided, even when viscous or paste like liquids are involved. The valves are composed of a cylindrical reinforced sleeve of natural or synthetic rubber assembled within the valve body. Valve closure is achieved by applying pressure, usually compressed air, which squeezes the sleeve into a flat configuration made possible by the pattern of the reinforcement. This ensures that the valve shuts tight. Standard sleeves are made of natural rubber with Neoprene or food grade rubber specified for hygienic applications. Special elastomer or Viton sleeves are also available for more abrasive media. The outer flanges of the valve are made from cast iron, while stainless steel plating with a Neoprene coating are other options.
