Diaphragm & Chemical Seal

A diaphragm seal, also known as a chemical seal, is a device fitted between a pressure gauge, pressure transmitter or pressure switch and the process. It uses a flexible diaphragm and fill fluid to isolate the instrument from the process media, protecting it from corrosive chemicals, high temperatures, viscous fluids and hygienic applications while maintaining accurate pressure measurement.

A diaphragm seal should be used whenever the process media could block, corrode or damage a pressure instrument. They are widely used in food and beverage production, pharmaceutical manufacturing, chemical processing, water treatment, oil and gas, and other demanding industrial applications.

Most pressure gauges, pressure transmitters and pressure switches can be supplied with a compatible diaphragm seal. The correct seal type, process connection and diaphragm material should be selected to suit the application and process media.

Diaphragm seals are available in a range of materials including 316L stainless steel, Hastelloy, Monel and PTFE-coated options. The material should be chosen based on the process fluid, operating temperature and chemical compatibility to ensure long service life and reliable performance.