Key Applications of Pressure Transmitters in the Petrochemical Industry

In petrochemical production, continuous operation, large-scale processing, and automation are the main trends. Pressure, as one of the most critical process parameters, is involved in nearly every unit. From crude oil distillation, catalytic cracking, ethylene cracking, ammonia synthesis, and methanol production, to downstream units like polymerization, distillation, and hydrogenation, pressure transmitters serve as both the “eyes” and the “nerves” of the process. They provide real-time pressure, differential pressure, and absolute pressure data to DCS/PLC systems, supporting safety interlocks, process optimization, and energy efficiency.

Shutdowns due to inaccurate pressure measurement or equipment failure in petrochemical plants can result in losses of millions or even billions. Therefore, the requirements for pressure transmitters in this industry far exceed ordinary industrial applications: extremely high long-term stability, wide environmental adaptability, strong anti-interference capability, and compatibility with corrosive, high-temperature, and high-pressure media are key considerations in selection.

Special Challenges of Pressure Measurement in Petrochemical Processes

The petrochemical production environment is complex and variable. Typical challenges include:

• Extreme conditions: medium temperatures can exceed 400℃, and pressures range from slight vacuum to tens of MPa;

• Strong corrosiveness: acids, bases, chlorides, hydrogen sulfide, and other substances can severely damage sensor materials;

• Crystallization, scaling, viscous media: can easily block impulse lines or contact diaphragms directly;

• High static pressure influence: significant zero drift in differential pressure measurements under high static pressure;

• High safety risks: explosive gas environments require intrinsic safety or explosion-proof certification;

• Long continuous operation cycles: maintenance cycles of 2–5 years, sensors must operate maintenance-free over extended periods.

Traditional transmitters often cannot meet all these requirements simultaneously. Modern intelligent pressure transmitters, through material innovations, structural optimization, and electronic advancements, are gradually addressing these pain points.

Core Advantages of Nexisense Pressure Transmitters in the Petrochemical Industry

• Material and structural adaptability: multiple diaphragm and flange materials available, including 316L, Hastelloy, tantalum, Monel, and duplex stainless steel; remote diaphragm structures effectively isolate corrosive media from the sensitive element;

• Wide temperature range and high stability: medium temperature -40℃ to +400℃ (higher for remote types), full temperature compensation, long-term stability ≤ ±0.1%FS/year;

• High static pressure and wide turndown ratio: static pressure up to 60MPa, turndown ratio up to 100:1, allowing one model to cover multiple process conditions;

• Intelligent communication and diagnostics: supports HART, FOUNDATION Fieldbus, Profibus PA protocols for two-way communication, remote parameter configuration, and self-diagnostics;

• Comprehensive safety certification: intrinsic safety Ex ia, explosion-proof Ex d, SIL2/3 functional safety certifications to meet petrochemical hazardous area requirements.

These features make Nexisense products perform excellently in actual projects, especially in typical petrochemical scenarios with high temperature, high pressure, strong corrosion, and scaling issues.

Specific Applications in Typical Petrochemical Units

1. Crude Oil Distillation and Atmospheric/ Vacuum Units

Used for monitoring pressures and differential pressures at the top, bottom, and side cuts of distillation columns. Remote diaphragm types are commonly used for high-temperature, corrosive media. Accurate differential pressure measurement ensures stable tray pressure drops and optimizes separation efficiency.

2. Catalytic Cracking and Delayed Coking

Pressure control in reactors, regenerators, and fractionation columns is critical. High-temperature transmitters (with heat sinks or remote designs) monitor regenerator and flue gas pressures, ensuring catalyst circulation and combustion balance.

3. Ethylene Cracking Furnaces and Gas Compression

Monitoring pressures at furnace tube outlets and compressor stages directly affects yield and equipment safety. Transmitters must have fast response, vibration resistance, and long-term stability.

4. Tank Farm and Storage Management

Monitor tank levels (via differential pressure), tank pressure, and purge gas pressures. Micro/low-pressure transmitters are commonly used for atmospheric tank vent control and nitrogen blanketing pressure maintenance.

5. Hydrogenation, Desulfurization, and Other Downstream Units

Pressure monitoring for high-pressure reactors (10–20MPa+); requires high static pressure performance and intrinsic safety/explosion-proof rating.

Technology Trends: From Traditional to Intelligent and Miniaturized

• MEMS micro sensors: small size, low power, strong integrated temperature compensation, advantageous for multi-point monitoring and portable equipment;

• Digitalization and predictive maintenance: more diagnostic data collected via HART/FF bus, supporting condition-based maintenance strategies;

• Wireless trend: some non-critical points adopt wireless transmitters, reducing wiring costs.

These advancements provide more accurate measurement, smarter maintenance, and higher safety assurance.

Conclusion

In the petrochemical industry, where safety requirements are high, economic stakes are large, and continuous production is critical, a reliable pressure transmitter often serves as the last line of defense for stable operation. It is not just a measurement element but also an integrated safeguard for process safety, product quality, production efficiency, energy savings, and environmental compliance.

Nexisense pressure transmitters, with deep understanding of petrochemical conditions and continuous technological iteration, provide stable support for increasingly large integrated refining, coal chemical, and new material chemical projects. In the pursuit of greener, smarter, and safer petrochemical operations, choosing a pressure transmitter that can withstand field conditions ensures continuous production reliability.