Diaphragm Ball valve

Diaphragm Ball valve

Diaphragm ball-valves, which are also referred to as BRS or Garston ball-valves, are specially developed to overcome the noisiness and inherent faults of the Croydon and Portsmouth valves. Since the moving parts of a diaphragm valve are protected from incoming water by the diaphragm there is no risk of them seizing as a result of scale deposits and the problem of noisy water delivery is often overcome nowadays by an overhead sprinkler outlet which sprays rather than squirts the water into the cistern. Diaphragm ball-valves are needed to adjust the water level in a cistern fitted with a diaphragm valve, and then invariably the float arm is bended. The only problems users are likely to encounter with diaphragm valves are jamming of the diaphragm against the valve nozzle, and obstruction of the space between the nozzle and diaphragm with debris from the main. The users can remedy these problems by unscrewing the knurled retaining cap and either freeing the diaphragm with a pointed tool or removing the debris.

Diaphragm ball valve is made up of body, body lining. Different parts have different material. For example, the body material is brass, cast iron, ductile iron, carbon steel, stainless steel and all kinds of plastic. The body lining materials are unlined type, rubber lined type and fluorine plastic lined type. They depends on temperature, pressure and chemical. As for diaphragm materials, there are NR/Natural Rubber, NBR/Nitrile/Buna-N, EPDM, FKM/Viton, SI/Silicone rubber,  FEP/F46,with EPDM back, PTFE/F4,with EPDM back and PFA,with EPDM back. Originally, the diaphragm ball valve is developed for use in non-hygienic applications. Later on the design it is adapted for use in the bio-pharmaceutical industry by using compliant materials that can withstand sanitizing and sterilizing methods. Diaphragm ball valves can be manual or automated. Their application is generally as shut-off valves in process systems within the food and beverage, pharmaceutical and biotech industries. The older generation of these valves is not suited for regulating and controlling process flows, however newer developments in this area have.