A diaphragm seal system in vacuum pressure process must master a major challenge ? it must deliver a reliable measuring result, even when the pressure drops and the temperature rises at the same time. pressure gauge 10 bar of a chemical company producing phthalic anhydride (PA) demonstrates it is in no way self-evident that requirement can be met on a consistent basis.
PA is primarily used as a plasticiser for plastics. However, additionally it is used in the production of synthetic resins and dyes. The plant operator obtains this compound via the catalytic oxidation of o-xylene in the gas phase, followed by a vacuum distillation process.
Critical phase for pressure measurement
In this technique, the critical phase for pressure measurement occurs in the distillation column. There, the procedure temperature can rise to a lot more than 230 �C as the pressure drops to 100 mbar abs. With this type of contrary action, the conventional installed measurement technology reaches its performance limit relatively quickly, that your aforementioned manufacturer was forced to learn ? all instrumentation showed a measurement deviation outside the defined tolerance after only week or two.
Diaphragm seal system adapted in every elements to the vacuum process
The diaphragm seal system is tailored exactly to the conditions of the vacuum process and tested under application conditions.
Consequently, the business approached WIKA with the request for a measuring solution that would also fulfil its task with the mandatory accuracy in the long run under the conditions described. WIKA then drew on เพรสเชอร์เกิจ -depth expertise to design a diaphragm seal system for the vacuum process, comprising an activity transmitter (model IPT-20), a flange-type diaphragm seal with flush diaphragm (model 990.27) and a capillary.
All components of this measuring system were selected designed for the application. Silicone oil KN32 was therefore selected because the fill fluid for pressure transmission. The cleaning and conditioning of the diaphragm seal, the capillary, the connection pieces as well as the automated filling process were also matched to one another exactly. With sensitive limit ranges, even one drop of liquid too much or inadequate can destabilise the volume balance of the diaphragm seal system and thus impair its function. Subsequently, correct measurement would no more be guaranteed.
Test under application conditions
After cleaning, all elements of the diaphragm seal system were first fully welded into a single unit as usual, followed by the filling and adjustment of the system. Before delivery, however, there was another crucial step ? in its laboratory, WIKA simulated a vacuum process for the diaphragm seal system relative to the customer?s conditions and subjected it to a thermal ageing process. pressure gauge octa confirmed the procedure suitability of the measuring system.
Note
Further information on the WIKA diaphragm seal systems can be found on the WIKA website. For those who have any questions, your contact will gladly assist you to.
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Just how do diaphragm seals work?
Watch the following video to learn more concerning the functionality, application areas and advantages of diaphragm seals: