The butterfly valve comprises a ring-shaped body in which a ring-shaped elastomer seat/liner is inserted. A washer guided through a shaft swings through a 90° rotary movement into the gasket. Depending on the version and nominal size, this enables operating pressures of up to 25 bar and temperatures up to 210 °C to be shut off. Most often, these valves are used for mechanically pure liquids, but can also be used in the right material combinations without posing any problems for slightly abrasive media or gases and vapours. 

Due to the large variety of materials, the butterfly valve is universally compatible, for example with countless industrial applications, water/drinking water treatment, coastal and offshore sectors. The butterfly valve is also often a cost effective alternative to other valve types, where there are no stringent requirements regarding switching cycles, hygiene or control accuracy. In large nominal sizes of greater than DN 150, it is often the only shut-off valve that is still viable. For more stringent demands with respect to chemical resistance or hygiene, there is the possibility of using a butterfly valve with a seat made of PTFE or TFM. In combination with a PFA encapsulated stainless steel disc, it is suitable for highly aggressive media in the chemical or semiconductor industry; and with a polished stainless steel disc, it can also be used in the foodstuff or pharmaceutical sector.

For all the valve types specified, GEMÜ offers numerous customized accessories for automation and process optimization. Electr. position indicator, position and process controllers, sensor systems and measurement devices, are easily and quickly fitted, adjusted and integrated in the existing process control technology.