In-line Diaphragm Seals

WIKA in-line diaphragm seals and sanitary pressure instruments are available in a wide range of measurement instruments.  The system eliminates any crevices that could trap product and inhibit cleaning.

In-line Diaphragm Seals

In-line diaphragm seals offer modular assembly for a wide range of pressure measurement instruments for critical pharmaceutical, biotech and food and beverage.

In-line diaphragm seals are used to protect cross contamination in a wide range of clean in place and sterilization in place applications  The spool piece is completely drainable and free of any dead spaces or crevices which would trap any product or condensate.  The connection of the measuring instrument is also protected from teh process.  For the material selection WIKA offers a variety of solutions, in which the upper body and the diaphragm are made of identical materials. Stainless steel 316L (1.4435) is used as standard material, other special materials are available on request.

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”. The model 981.22, 981.52 and 981.53 in-line diaphragm seals with clamp connections, due to their circular design, can be mounted directly into the pipeline, meaning no special measuring point connection is required. Through the integration into the process line, turbulence, dead spaces, corners and other obstructions can be avoided. For this diaphragm seal WIKA uses a completely round diaphragm,
which, due to the unobstructed flow of the media, produces an automatic cleaning of the chamber. The diaphragm seal systems can withstand the cleaning
vapor temperatures occurring in the SIP processes and thus ensure a sterile connection between the medium to be measured and the diaphragm seal. 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.


The WIKA group of companies is a worldwide leader in pressure and temperature measurement. The company also sets the standard in the measurement of level and flow, and in calibration technology. Founded in 1946, WIKA is today a strong and reliable partner for all the requirements of industrial measurement technology, thanks to a broad portfolio of high-precision instruments and comprehensive services. With manufacturing locations around the globe, WIKA ensures flexibility and the highest delivery performance. Every year, over 50 million quality products, both standard and customer-specific solutions, are delivered in batches of 1 to over 10,000 units.

The in-line diaphragm spool piece is particularly useful for processes which incorporate clean in place and steam in place sterilization. In-line diaphragm seals are used to protect the pressure measuring instrument from aggressive, adhesive, crystallizing, 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.

Please call PharmaAseptic or visit the Rattiinox web site for additional information