Diaphragm seals are used for the protection of pressure measuring instruments in applications with difficult media. In diaphragm seal systems, the diaphragm of the diaphragm seal effects the separation of the instrument and the medium. The pressure is transmitted to the measuring instrument via the system fill fluid which is inside the diaphragm seal system. For the implementation of demanding customer applications, there is a wide variety of designs, materials and system fill fluids available. For further technical information on diaphragm seals and diaphragm seal systems see IN 00.06 "Application, operating principle, designs". Thanks to its flush process connection, the model 990.17 diaphragm seal is optimally suited for installation in storage tanks. With a suitable welding flange, this diaphragm seal can

be integrated into any type of tank or vessel. Level measurement with diaphragm seals also works with media that, due to the process, are under pressure and have high or low viscosity.
The model 990.17 diaphragm seal is particularly suitable for CIP cleaning processes as it meets the requirements for elevated temperatures and chemical resistance to cleaning solutions. Mounting of the diaphragm seal to the measuring instrument may be made via a direct connection, for high temperatures via a cooling element or via a flexible capillary. For the material selection WIKA offers a variety of solutions, in which the diaphragm seal and the wetted parts can be made of identical or different materials. The wetted parts can, as an alternative, be electropolished.