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  • HOW TO SELECT FILL FLUIDS FOR DIAPHRAGM SEALS

Making the right diaphragm seal fill fluid selection is important. You understand your process and parameters well, but having a partner to assist you is always helpful. ESP will supply detailed data to help inform your decision regarding the type of system fill fluid you use. Outside of direct advice from ESP, there are several principles to keep in mind.

The Foundation of Fill Fluid Choice

When choosing a system fill fluid, you must base your decision on several factors. These include the pressure, process media, and temperature. Additionally, the type of application must be considered. ESP is happy to provide you with detailed information regarding all of these factors upon request. Don’t hesitate to reach out to us for additional details regarding the fluid selection process.

Common Fluid Types and Typical Applications

There are many diaphragm seal fill fluid types available. Each type of fluid fulfills a specific purpose and is typically ideal for use within a certain set of applications. For example, Vaseline and mineral oil are used in food and pharmaceutical applications, as well as all standard devices. They are approved for use by the FDA.

There are many silicone seal fill fluid types to consider. Silicone DC510-100 is ideal for low-temperature use, while silicone DC550-100 is used with high temperatures. Silicone DC200-10 is generally used with low-viscosity fluid and causes a reduction of response time. Silicone DC704 is used for vacuum and absolute pressure measurements. For high-temperature use in process measurement transmitters with reduced response time, silicone Slytherm 800 is ideal, while low-temperature silicone may be used in very cold applications.

Fluorocarbon works with any device used on an oxygen or chlorinated circuit (P max. 160 bar). For glycerin plus water, use paint without silicone or vacuum. Finally, use paraffin oil for sanitary purposes; it is FDA-approved.

Feel Confident in Your Decision

Once you choose the right diaphragm seal fill fluid for your particular process, you’ll feel more confident that your investment in your pressure instruments is secure. As always, ESP is happy to provide data-driven guidance to assist with your selection, but the most important thing to bear in mind is that the type of fluid you select will be based on your specific requirements. Make your seal fill fluid choice with confidence, knowing that it will work correctly in conjunction with the use of a high-quality diaphragm seal from ESP.