ARTiS Reformer Tube Inspection per API 579-1/ASME FFS-1

ARTiS, Automated Reformer Tube Inspection System

ARTiS, the Automated Reformer Tube Inspection System, is the flagship robotic intellectual property of the TCR Group: developed and patented by TCR Advanced Engineering and deployed group-wide across India, the GCC, and international reformer fleets. The system carries reformer tube inspection through a helical scan with embedded Fitness for Service reporting per API 579-1/ASME FFS-1 and API 530.

With 80+ reformer inspection assignments completed for Indian and overseas clients and 50,000+ tubes scanned, TCR anchors the group's reformer tube integrity practice. The practice rests on a proprietary data bank of reformer tube failure mechanisms built over decades of failure investigations, which allows TCR to recognise the early warnings of tube failure, and on a unique combination of operational understanding and metallurgical interpretation of reformer service. The assessment answers the question every reformer owner actually asks: when to retire each tube.

ARTiS is a TCR-built robotic crawler that automates the ultrasonic inspection of primary reformer tubes in place of manual scanning. It runs ultrasonics in transmit-receive (T-R) mode: energy passes from one sensor through the tube wall to a second sensor, and the energy lost to beam scatter is the measurement. In an as-cast tube that scatter comes from dendrite boundaries and primary carbides; after long high-temperature service, secondary-carbide precipitation and creep voids add to it.

TCR reads the resulting attenuation against calibrated bands: 35 to 55 dB for virgin structure, 55 to 62 dB for aged structure, and 62 to 72 dB at a life fraction of 80 to 95 percent, where secondary carbides have coarsened and inter-dendritic micro-cracks appear. The crawler is driven by four metal-gear motors rated 200 watts in total, with a rubber-padded shoe carrying the transmit-receive probes, infra-red sensors for diameter, and gyroscopic sensors for bowing. It scans 10 metres in 2 to 5 minutes at 100 mm resolution, fixes in 3 minutes, and climbs to 15,000 mm, accommodating tube outer diameters of 70 mm to 200 mm with the current crawler generation (105 mm to 190 mm on the earlier generation) and walls of 8 to 20 mm. The 25 mm, 1 MHz probe runs a 30 to 100 dB range at 0.1 dB resolution, with diameter resolved to 0.5 percent of outer diameter and bowing to 5 mm.

Against manual scanning, ARTiS removes the scaffolding requirement and inspects 100 tubes in about 2 days rather than 4 to 5, reports continuously at 100 mm resolution rather than in six-foot segments, measures outer diameter every 100 mm rather than at one or two points by hand, and returns a quantitative bowing figure of 5 to 200 mm rather than a visual estimate.

Inspection Scope Per Tube

ARTiS is a multi-technique assessment. Every tube in the radiant box is examined through nine coordinated measurements, and TCR calibrates the crawler against proprietary standard samples with known damage scenarios, which gives the attenuation readings a validated reference that single-technique providers cannot match. The scope per tube covers:

• Expert visual inspection of every tube for general appearance, bulging, baldness, sagging, and bowing.
• Outer diameter measurement by the on-board electronic infrared sensors on the crawler, recorded at 0.1 metre intervals over the full tube height.
• Bowing measurement by the on-board electronic instrumentation on the crawler.
• Ultrasonic attenuation measurement in decibels for mid-wall fissure detection, run by the automated crawler in transmit-receive mode.
• In-situ metallography to establish the stage of microstructural degradation.
• Hardness measurement at each metallography location.
• Manual ultrasonic wall thickness measurement of all tubes at one location at platform (bottom) level.
• Manual outer diameter measurement of all tubes at platform (bottom) level.
• Manual magnetic permeability measurement of all tubes at platform (bottom) level.

Level 3 Fitness for Service Deliverables

The inspection feeds a Level 3 assessment per API 579-1/ASME FFS-1, delivered tube by tube. The report package carries:

• The complete inspection results across all nine measurement streams.
• A summary table of accumulated creep damage for every tube as on the date of inspection.
• The calculated effective tube metal temperature for each tube.
• Where sufficient life is available, the theoretical accumulated creep damage projected to the next shutdown.
• The date of tube replacement at which accumulated creep damage exceeds the 0.8 life fraction.
• The remaining life of each tube.

The effective tube metal temperature is the anchor of the remaining-life mathematics. It is defined as the temperature that caused the present level of creep damage in terms of creep strain, accommodating occasional changes in tube skin temperature and thermal cycling; it is not the same as the pyrometer reading taken on the tube skin. Future life expectancy is acutely sensitive to it: field experience shows that an overshoot of 10 to 20 degrees Celsius above design can cut tube life substantially, which is why the ARTiS report carries a sensitivity analysis showing expected life at 10, 20, and 30 degrees Celsius above design for the worst tubes. That sensitivity table is what turns an inspection record into an operating decision: timely tube-replacement calls, budget allocation across tube and catalyst replacement, inventory build-up, and realistic downtime planning for the next turnaround.

Reference Engagements

Beyond the engagements above, ARTiS has been deployed across the Indian refining and fertiliser reformer fleet and at international sites. Reference sites for reformer tube inspection using ARTiS include:

Authority Anchor

The ARTiS paper by Upadhyaya, Haribhakti, Patel, and Bafna (TCR Advanced, 2013 to 2014) is the published authority anchor for the practice.

The practice is also published in the international trade press: 'Optimising Tube Life' by Paresh Haribhakti and Ketan Upadhyaya of TCR Advanced Engineering, World Fertilizer Magazine, January/February 2019, covering operational control for the enhancement of reformer tube life and the role of automated reformer tube inspection.

Related services and industries

• Fitness-for-Service
• In-Situ Metallography
• Remaining Life Assessment
• Fertilisers
• Refining and Petrochemicals
• Chemicals

Related insights

4 of the 86 published insights tagged to Asset Integrity bear directly on ARTiS Reformer Tubes. The 4 most relevant are below.

Read all 86 Asset Integrity insights →All insights →

Documents

Download the reference documents for this page. Every file is hosted on this domain and is also listed in the site document library.

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  ARTiS Reformer Tube Inspection and Remaining Life Assessment

  42 pages: the four ARTiS measurements, the damage classification and the Level III remaining life assessment to API 579-1/ASME FFS-1

  PDF (2.9 MB)