Sealing Structure and Long-Term Stability Assurance of Explosion-Proof Pressure Transmitters

In hazardous locations such as petroleum, chemical, natural gas, and pharmaceutical facilities where flammable and explosive gases or dust are present, explosion-proof pressure transmitters serve not only as critical process measurement instruments but also as vital safeguards for production safety. Their long-term operational reliability hinges significantly on the design of their sealing structure and material selection. Seal failure not only leads to measurement inaccuracies but may also trigger medium leakage, potentially causing safety incidents.

I. Multi-Seal Design as the Foundation of Safety

Explosion-proof pressure transmitters UPB9 typically employ a "triple-seal" strategy:

1. Process Interface Seal: Utilizes metal gaskets (e.g., 316 stainless steel spiral wound gaskets) or fluororubber O-rings to ensure high-pressure resistance and corrosion resistance at pipeline connections;

2. Electronics Chamber Seal: A highly elastic fluorosilicone O-ring is used between the housing and cover plate. Uniform clamping via bolts achieves IP66/IP67 protection ratings.

3. Electrical Lead Seal: The cable entry is equipped with an explosion-proof gland. The interior is potted with epoxy resin or silicone to prevent combustible gases from entering the chamber along the cable.

II. Material Compatibility Determines Service Life

Transmitter diaphragms and seals must exhibit high compatibility with the measured medium. For instance, in oil and gas environments containing hydrogen sulfide (H₂S), diaphragms are typically made of Hastelloy C-276 or tantalum; seals prioritize perfluoroelastomer (FFKM), which withstands temperatures up to 300°C and offers exceptional resistance to strong acids and solvents, significantly extending service life.

III. Enhanced Reliability Through Welding and Encapsulation Techniques

Explosion-proof transmitters UIB5 widely adopt laser welding to replace traditional threaded connections, eliminating potential leakage points. Simultaneously, circuit boards undergo triple-proof coating (moisture-proof, mildew-proof, salt-spray-proof) before full encapsulation. This effectively blocks moisture and corrosive gas ingress, preventing performance drift caused by condensation or electrochemical corrosion.

IV. Long-Term Stability Verification Mechanism

Product stability is typically validated through accelerated aging tests (such as high-temperature/high-humidity cycling and pressure shock testing) and long-term drift tests. Users should also perform regular zero-point calibration and seal integrity checks during operation, particularly under conditions involving frequent start-stop cycles or significant temperature fluctuations.

In summary, the sealing structure of explosion-proof pressure transmitter UIB6 serves not only as a physical barrier but also as a core component of functional safety. Only through scientific material selection, precision manufacturing, and standardized maintenance can the industrial objectives of "accurate measurement, long service life, and guaranteed safety" be truly achieved.

For more information, please contact Qi Huang: qihuang@utopsensor.com.