Job Overview
Arise Global performed an Acoustic Pulse Reflectometry (APR) non-invasive inspection on an auxiliary boiler & 3rd stage suction cooler tubes at a FPSO in Ghana consisting of 672 and 795 tubes respectively. The primary reasons for selecting an Acoustic Pulse Reflectometry inspection were based on the following:
- Non-Invasive & Easy access: Acoustic waves could propagate in any configuration using air as a medium
- Accuracy & Speed: Defect type, its size and location could be reported precisely & 100% inspection in limited time frame.
The auxiliary boiler which we had inspected was 20 years old and has 2 times the capacity of top side (main) boiler. Riser tubes/ Generating tubes as well downcomer tubes were inspected by us within few hours and reports furnished instantly. Conventional technologies couldn’t inspect such tubes easily because of the tube ID variations at beginning & throughout the tube. Similarly, suction cooler tubes were also inspected within 3 hours and report furnished on same day evening.
Summary of Inspection Results
| Tube Size | Riser Tube(50.8mm) OD: Downcomer (139.8mm) OD: Cooler Tube (19.05mm) |
| Tube Thickness | Riser Tube (4.5mm); Downcomer (6.6mm); Cooler Tube (2.5mm) |
| Tube Length | 7m (Avg. length of a boiler tube);4.3m (Total Length of a cooler tube) |
| Tube Shape | Special configuration (Boiler Tube); Straight (Suction Cooler Tube) |
| # of Tubes | 672 (Boiler Tubes); 795 (Suction Cooler Tubes) |
| Defects Found | Boiler Tube Suction Cooler Tube Pits >80% : 2 Pits 40-60% : 4 Pits 60-80% : 9 Pits <40% : 55 Pits 40-60% : 27 Erosion<40% :2 Pits<40% : 53 |
| Inspection Time | 6 hours (100% Boiler Tubes); 3 hours (100% Suction Cooler Tubes) |
Outcome
- All tubes with pitting >60% were plugged.
- Operating efficiency of boiler reached its maximum after 1-month downtime and decided to have periodic inspection to monitor the defect rate.
Tube Sheet Diagram
About APRIS’s Non-Invasive Inspection
With APRIS’s breakthrough capabilities for inspecting today’s most challenging tube sizes and configurations up to 4”, it is possible to inspect boilers, Fin Fans and other heat exchangers in any shape or material. Ultra-fast, accurate testing can be performed at a fraction of typical inspection cycle times and without extra inventories of consumable probes and standards. Utilizing Acoustic Pulse Reflectometry (APR) technology, APRIS is a very advanced yet easy-to-use tool. With its simple operation, automated analysis and report generation, there are minimal training requirements and far less dependency on operator expertise.
Defect Examples
APR Defect Identification
