For years refinery and chemical plant operators have utilized ultrasonic-based intelligent pig technology to inspect coils in convection and radiant sections of fired heaters. This proven technology provides accurate inspection data which allows reliability engineers to make critical decisions about the operation and maintenance of fired heaters. Recent advances have increased the capabilities of these tools and extended these benefits to coker heaters containing 3” (76.2mm) nominal piping size and plug headers with radial inserts.
Accurately assessing the condition of fired heater coils has proven challenging due to several factors. Conventional Non-Destructive Testing (NDT) methods, such as manual ultrasonics (UT), are ineffective in accurately assessing 100% of the internal condition of fired heater coils. The process is further complicated by coil lengths in excess of 1,524m (5,000’), raised surfaces such as studs and fins, multiple short radius 1D x 180° return bends, and inaccessibility.