Petroleum and Chemical Industry

Petrochemical production is characterised byhigh temperature and pressure, severe corrosion, and flammable and explosive atmospheres. Main units such as atmospheric and vacuum distillation, catalytic cracking and hydrocracking are mostly located in explosive gas atmospheres, so field instruments must meet explosion protection safety requirements in addition to measurement accuracy; moreover, units run continuously 24 hours a day, and any spurious signal or instrument failure can cause unplanned shutdown, with losses counted in hours. Common challenges:Intrinsic safety design and certification thresholds for hazardous-area loops are high; DCS, PLC and SIS systems coexist, with mixed 4–20 mA, HART and discrete signal types; outdoor tank farms and long-distance cables are susceptible to lightning surge impacts; bearing temperature measuring points on pumps and compressors are scattered, and cabinet wiring is congested. Our solution:Intrinsic safety barriers form the intrinsically safe interface, safely bringing hazardous-area signals into the central control room in compliance with the requirements of GB/T 3836 and IEC 60079 series for intrinsically safe loops; HART interfaces and signal isolators are paired to perform signal isolation, distribution and one-to-one conversion, avoiding measurement drift caused by earth circulating currents; switch amplifiers replace in-cabinet relays, providing contactless output with wire-break monitoring; temperature transmitters and temperature sensors cover pipeline, column and unit temperature measurement; surge protective devices provide graded protection for power and communication lines; H system remote I/O enables local acquisition, significantly reducing long-distance cables and in-cabinet wiring. The complete solution makes field loopsintrinsically safe design compliant, signals of each system free from mutual interference, and fault points traceable at an early stage, providing reliable support for long-term unit operation.

• Temperature and pressure loops and control valve interlocks for atmospheric/vacuum distillation and catalytic units
• Tank farm level, emergency shut-off valve and fire & gas alarm loops
• Bearing temperature monitoring for compressors, pumps and fans
• Surge protection for substations, communication lines and outdoor instruments