Becht Engineering has significant expertise in brittle fracture assessments. We hold over 40 positions in ASME, API, and ASTM Codes and Standards Committees, and have chaired many of them. Bob Sims was one of the original developers of the API 579-1/ASME FFS-1 guideline document. A number of our experts are current or past members of the API 579-1/ASME FFS -1 committee, including several committee vice-chair members.
Fracture mechanics and brittle fracture assessments are used in two different situations, Fitness-For-Service and Design of Section VIII, Division 3 vessels.
Our Brittle Fracture Assessment Methodology evaluates the potential for brittle fracture in vessels subject to colder operation using Levels 2 and 3 assessments, as well as those with existing cracks to be evaluated for fatigue life, using a Level 3 assessment. Our approaches are compliant with API 579-1/ASME FFS-1 and ASME Section VIII, Division 3 fracture mechanics methodologies for brittle fracture and fracture mechanics. Our web-based software is designed to facilitate rapid computation of the minimum allowable temperature (MAT) curve from 0 to design pressure, and compare with applicable fluid depressurization curves and the site’s critical exposure temperature (CET).
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Level 2 Brittle Fracture Assessment
Example Projects for Brittle Fracture
Becht has performed many studies and reviews involving brittle fracture, such as:
Level 2 brittle fracture review of over 2,000 pressure vessels for an international petrochemical company. These vessels had not been designed for the low temperatures that could occur as a result of auto-refrigeration. Most of these assessments were based on API 579, Level 2 methods and were performed very rapidly using our custom FFS software.
- Customized depressurization curves using client data
- Assisted with procedures for developing engineering and administrative controls for protection of the vessels.
Level 2 brittle fracture review of 70 pressure vessels for a US based chemical company.
- Calculated stress ratios using Compress to help lower the MSOT by using the stress ratio approach in API-579/ ASME FFS-1 Part 3.
Level 2 & 3 brittle fracture review of 120 pressure vessels for an olefins plant.
- Customized depressurization curves for auto-refrigeration events and plotted these versus the master temperature curve of the vessel.
- Calculated stress ratios using Compress.
We utilize our proprietary API 579 Fitness for Service software package. Our software was developed for performing brittle fracture screening, fracture mechanics, pitting and local/general metal loss analyses.
- Brittle Fracture per API 579-1/ ASME FFS-1 Part 3, Levels 1, 2A, 2B, 2C
- Fracture Mechanics per API 579-1/ ASME FFS-1 Part 9 & ASME VIII, Div 3, Article KD-4
- General Metal Loss per API 579-1/ ASME FFS-1 Part 4, Levels 1 and 2
- Local Metal Loss per API 579-1/ ASME FFS-1 Part 5 and B31G, Levels 1 and 2 5) Pitting per API 579-1/ASME FFS-1 Part 6, Level 1 6) Additional MAWP and T-min calculations
- Pitting Level 1 per API 579-1/ASME FFS-1, Part 3
- Weld Misalignment per API 579-1/ASME FFS-1, Part 8