Richard D. Roberts: About the Author
Quest Integrity Group

Refineries and chemical plants own and operate numerous process heaters (e.g. gas reformers, CCRs, etc.) as part of the standard assets throughout the facilities. Many heater coil configuration designs are flanged at both ends; however, there are also coil designs which contain common headers, linking the individual coil passes together at the inlet, outlet, or even at both ends in some cases.

Various fired heater designs in refineries and chemical plants contain common headers (e.g. Arbor coil configurations, CCRs, etc.) as part of their overall serpentine coil design. Accessing the interior of individual coils through the common header is challenging; however, advanced engineering firms and mechanical decoking companies have developed unique common header snorkel delivery systems.

The refining industry has applied ultrasonic-based intelligent pigging to inspect serpentine coils in fired heaters since the 1990s. Today, thousands of serpentine coils in fired heaters are inspected annually at process facilities around the globe.

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.

Part 1 in this 2 parts series laid the technical foundation for the methodology and technology. Part 2 will now demonstrate both through actual applications.

Having the ability to substantially extend tube life in Steam Reformers is essential in maximizing use of capital investments in Methanol, Hydrogen, and Ammonia Plants. With the price of nickel at an all time high, the cost of installing a single reformer tube upwards $20,000 USD.However, in today's highly competitive markets the effect of the unplanned downtime in reducing the plant on-stream factor is far greater than the installed cost of a single reformer tube.

Reliable "intelligent pig technology" is now readily available to the refining industry which can provide quick / comprehensive inspection to both "convection" and "radiant" sections in process furnace piping coils. Both tabular data formats along with 2D / 3D high-resolution color graphics of the test results are immediately produced on site showing tube/pipe wall thinning, bulging, swelling, and ovality.

Steam reformers are an integral part of ammonia, methanol, hydrogen, and gas process plants around the world. THey are one of the highest cost, both in capital and maintenance, pieces of equipment in the plant. Typically, reformers contain several hundred vertically oriented straight tubes, referred to as catalyst tubes. These tubes represent a significant cost for replacement and can be a major source of plant unavailability if unplanned failures occur.

Part 1 included a review of current tube inspection practices in convection and radiant sections of heaters/furnaces in the refining and chemical industries. The authors also presented a new inspection device combining laser image mapping of the internal surface of tubes and ultrasonic thickness mapping.

Furnace tubes in the petrochemical and refining industries lengths' can exceed 2,000 ft., often with multiple serpentine bends. This can make them extremely difficult to inspect using conventional NDE methods. The following inspection tool (FTIS) employs the combined capabilities of high-speed laser and advanced ultrasonic wall thickness measurements and is propelled through the piping via a column of clean water which provides a path for the laser beam, and the coupling for the ultrasonic signals.