DIAPHRAGM SEAL INSTALLATION AND MAINTENENCE
1.A diaphragm seal is a device that attaches to the process side of a pressure-measuring instrument to separate the instrument from the process fluid while transmitting pressure across a flexible membrane. The volume enclosed by the diaphragm, the top housing, and the measuring element is completely filled with a pressure transfer fluid. A change in pressure at the process connection causes a displacement of the filling fluid due to deflection of the diaphragm, transferring the change in pressure to the sensing element of the pressure instrument.
2. Safety Information WARNING: Serious injury or equipment damage can result from failure to properly install, maintain, or operate these components. To assure safe operation and maintenance procedures, read carefully and follow the instructions in this manual. • Follow all instructions in this document to avoid exposure to pressurized fluid • Use proper tools and safety equipment in installing or maintaining components • Assure that process pressure and temperatures are properly monitored and maintained, and the process fluid is appropriate and compatible with the wetted materials of the diaphragm seal • Follow all of your company’s safety procedures in the event of a leak or diaphragm seal failure.
3. A diaphragm seal can be filled using an oil can. The diaphragm should be flexed gently using a finger or a pencil eraser on the process side to purge entrapped air. Filling an instrument is done in the same way as the situation where the instrument and diaphragm seal are already assembled.
