Expanded Explanation of Chemical Seals
Chemical seals, also known as diaphragm seals, are crucial components used in pressure measurement systems. They serve as a protective barrier between a pressure-sensitive instrument (such as a pressure gauge, transmitter, or switch) and the process media. By isolating the instrument from direct contact with the process fluid, chemical seals ensure the longevity, accuracy, and reliability of the measurement system in challenging environments.
Functions of Chemical Seals.
Blockage Prevention:
Process media such as sludge, slurry, or viscous liquids can clog an instrument’s pressure entry port. Chemical seals prevent such blockages by keeping the entry point clear.
Corrosion Protection:
Many process media are highly corrosive, and direct contact can damage sensitive components of the instrument. A chemical seal acts as a barrier, protecting the instrument from chemical attack.
Hygienic Applications:
In industries like food and pharmaceuticals, maintaining a sanitary environment is critical. Chemical seals prevent the process fluid from entering and contaminating the pressure instrument.
Temperature Isolation:
Chemical seals can protect instruments from extreme process temperatures by creating a buffer zone or by using fill fluids that resist temperature effects.
Compatibility with Exotic Media:
For media that are highly reactive, toxic, or otherwise unsuitable for direct contact with conventional instrument materials, chemical seals provide a solution by incorporating special materials for the diaphragm, such as Teflon, Hastelloy, or titanium.

How Chemical Seals Work:
A chemical seal consists of a thin, flexible diaphragm that isolates the process media. Behind the diaphragm is a fill fluid, which transmits the pressure to the sensing element of the instrument. The fill fluid ensures accurate pressure transmission without exposing the instrument to the process media.
Industries and Applications:
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Chemical and Petrochemical Industries:
- Measure pressure in highly corrosive or hazardous environments.
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Food and Beverage Industry:
- Ensure sanitary conditions while measuring pressure in processes like fermentation or bottling.
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Pharmaceuticals:
- Maintain sterile conditions for applications involving sensitive drugs or formulations.
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Water and Wastewater Treatment:
- Protect instruments from contaminants and aggressive cleaning agents.
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Oil and Gas:
- Withstand the harsh conditions of exploration and refining processes.
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Power Generation:
- Handle high-temperature and high-pressure applications in boilers and turbines.
Benefits of Chemical Seals:
- Prolonged instrument life by shielding it from harmful process conditions.
- Enhanced measurement accuracy in aggressive or unstable environments.
- Increased safety when dealing with toxic or hazardous media.
- Improved compliance with industry standards and regulations, especially in hygienic and sterile processes.
Customization:
Chemical seals can be tailored to meet specific application needs, including:
- Diaphragm material selection based on media compatibility.
- Selection of fill fluids for high temperature or high-pressure applications.
- Special mounting configurations for challenging setups.
Chemical seals are essential in industrial processes, ensuring precision and durability while safeguarding instruments from adverse conditions.
We also offer SANAS traceable calibrations complete with a certificate, valid for 1 year on our premises.
Blanes Pressure Solutions supplies a comprehensive range of pressure measurement instruments.
Blanes Pressure Solutions was founded in 2002 to take over the pressure business of Blanes Instruments CC, and can trace its pedigree back to 1893, when Robert Blane left Scotland to make his fortune on the Witwatersrand.
For more information on placing orders, after care and maintenance services you can contact our Sales Manager Ronel Olivier on ronel@pressuresolutions.co.za or 011 422 1749.