Critical vessels are key process units in chemical and refinery operations. They include gasifiers, steam methane reformers, reactors, distillation columns, and pressurized storage tanks, among other vessels. They typically handle high pressures, temperatures, or hazardous materials, making their integrity essential to safe and reliable plant operations. 

Monitoring these vessels plays an important role in the organization’s broader Asset Integrity Management strategy. A comprehensive vessel monitoring system uses a range of tools, technologies, and approaches to detect abnormal operating conditions, structural issues, or other potential failures. 

Unfortunately, many of the traditional tools and approaches fail to provide comprehensive coverage of the entire vessel. Without access to continuous temperature data, operators may not be able to detect the telltale signs of failure before it’s too late. 

Thermocouples are point-based temperature sensors used to measure localized temperatures on or within process vessels. They are common in chemical production facilities and refineries and are typically installed in thermowells or directly embedded in vessel walls. 

Thermocouples offer useful localized temperature data but lack the coverage, resolution, and robustness needed for comprehensive vessel monitoring. They cannot detect anomalies that occur between sensors, allowing minor issues to grow into more severe failures. Further, because they come into contact with the vessel, they are subjected to vibration, heat, and corrosion, making them prone to fatigue or failure. 

Thermocouples are difficult to install and require frequent calibration, maintenance, and repairs, all of which necessitate downtime so that technicians can safely access the vessel. 

In contrast to thermocouples, fiber optic temperature sensing systems allow for distributed temperature measurement along the entire length of the fiber. They measure how light signals change along the length of the optical fiber, allowing temperature data to be captured at many points. This makes it possible for operators to detect temperature gradients, hotspots, or other anomalies across the surface of the vessel. 

Despite this broader coverage, fiber optic systems still only measure temperature along the fiber path, meaning they are also prone to missing localized anomalies or hotspots around the vessel circumference. Moreover, they require highly precise installation and can be difficult to maintain and use. Specialized software and expertise are needed to interpret and use the data, limiting an operator’s ability to quickly understand the health and performance of the vessel. 

Physical inspections are commonly used to assess the structural integrity, surface condition, and overall health of critical vessels. They remain fundamental to Asset Integrity Management and regulatory compliance programs, and they are still useful for baseline and post-maintenance validation.

However, physical inspections are costly and labor-intensive, requiring workers to access hazardous areas where they could be exposed to high temperatures, toxic chemicals, or other dangerous conditions. They can only be performed during shutdowns or asset turnovers, further increasing total cost. Finally, because they occur intermittently, issues that develop between inspections may go undetected and unresolved, resulting in catastrophic failure.

Continuous Critical Vessel Monitoring solutions leverage advanced thermal and visual cameras to provide 24/7 coverage of the entire vessel. 

Compared to traditional tools, Continuous Critical Vessel Monitoring solutions are reliable, non-intrusive, and easy to use. They provide operators with a simple visualization of exterior vessel temperature so they can optimize production and mitigate the risk of failure. With greater access to both historical and real-time data, operators can detect anomalies, diagnose potential issues, adjust inputs, and mitigate the risk of catastrophic failure.

To learn more about Continuous Critical Vessel Monitoring solutions and see how they can be deployed for a range of applications in refineries and chemical manufacturing facilities, download our recent white paper: Improving Safety and Reliability in Petrochemical Plants With Continuous Critical Vessel Monitoring.