Diaphragm seals are used to protect the pressure measuring instrument from aggressive, adhesive, crystallising, corrosive, highly viscous, environmentally hazardous or toxic media. A diaphragm made of the appropriate material provides for the separation from the medium to be measured. Thus even the most difficult measuring requirements can be met by combining measuring instruments with diaphragm seals.
A fluid inside the system, which can be chosen to suit the particular application, hydraulically transmits the pressure to the measuring instrument.
Almost limitless application possibilities exist due to the large number of available variants, such as diaphragm seal designs or materials. The type of process connection (flange, threaded and sterile connection) and the basic method of manufacture are important design differentiation criteria.
For further technical information on diaphragm seals and diaphragm seal systems see IN 00.06 "Application, operating principle, designs".
Due to its design, the model 990.27 diaphragm seal with flange connection and flush diaphragm is suitable for all currently used standard flanges and is mounted for pressure measurement in lieu of a blind flange.
Assembly of the diaphragm seal and measuring instrument is made via a direct assembly as standard or optionally via a cooling element or a flexible capillary.
For the material selection WIKA offers a variety of solutions, in which the upper part and the diaphragm can be made of identical or different materials. The diaphragm and the sealing face can also be offered coated or covered with foils.
Measuring systems with model 990.27 WIKA diaphragm seals are successfully used worldwide in the chemical process and petrochemical industries with high measuring requirements.