Applications
·
For assembly (direct assembly, via a cooling
element or a capillary) with measuring instruments for low pressuresand with
differential pressure measuring instruments
·
For aggressive, contaminated or hot media
·
Chemical process industry, petrochemical industry
·
Level measurement, filter monitoring
Special Features
·
Internal diaphragm with large working volume
·
Special materials available
·
Low temperature error due to large diaphragm
diameter (realisation of low measuring ranges possible)
·
Wide temperature application range due to large
working volume
·
Integrated flushing connections (optional)
Description
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".
The model 990.41 diaphragm seal with flange connection and
internal diaphragm is ideally suited for applications with small process
connections. Due to the internal diaphragm (large diaphragm diameter) low
measuring ranges can be realised. When the temperature changes, the diaphragm
counteracts the volume expansion of the system fill fluid, thus ensuring a
lower deviation at the measuring instrument.
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 body, the diaphragm and the lower body can be
made of identical or different materials. The diaphragm and the lower body can
also be offered coated or covered with foils.
Measuring systems with model 990.41 WIKA diaphragm seals are
successfully used worldwide in the chemical process and petrochemical
industries with high measuring requirements.