Diaphragm valves are suitable for complete opening/closing as well as for flow control and can therefore be used in the pharmaceutical industry, in the general and (petro)chemical industry, in the food industry and in the utilities sector.
One advantage of the diaphragm valves is their efficient maintenance. They also feature a simple modular construction, which does not show any dead space. Thanks to their soft seal, diaphragm valves are also 100% leak-free. In addition, a diaphragm valve can be easily fitted with a pneumatic actuator and a wide selection of diaphragm and lining materials is available.
Diaphragm valves can be used with both clean and contaminated gaseous products, as well with solid materials. The moving parts of the operating mechanism do not come into contact with the product. This means that the valve is consistently easy to operate and ensures a long service life.
The diaphragm is the heart of the diaphragm valve. The diaphragm ensures ease of operation and—if combined with a lining—guarantees compatibility with the product. A diaphragm consists of several layers of rubber with fibre reinforcements. Under the right temperature and pressure conditions, these rubber layers are vulcanised to form a single unit. The correct assembly arrangement or mixture as well as the production process guarantee the flexibility, mechanical strength and chemical resistance of the diaphragm.
A wide range of different diaphragm and lining materials is available and both the performance and the service life of the diaphragm valve are determined by the correct choice of material.
Most industrial diaphragm valves are bridge-style valves. The model with a straight bore is mainly used for highly abrasive products, greater volume flows and solid materials. In the flange model, the valves are completely made of stainless-steel cast iron, ductile cast iron or plastic. The model with threaded connections is also available in bronze.
The diaphragm valve is designed with no dead space, making it the ideal valve for pharmaceutical process systems. In addition to adhering to strict guidelines regarding construction, traceability of any materials that are used is compulsory in this industry. Many diaphragm types are therefore also available with FDA, EC 1935 or drinking water certification as well as a traceability certificate.