ODonnell Consulting

Fitness for Service Evaluations

Fitness for Service Evaluations

Asset Integrity Management includes Fitness for Service evaluations to relevant Codes to determine whether equipment with existing flaws (such as distortions or cracks) found by inspection is suitable for continued service. Fitness for Service evaluations are the most viable step in determining the safety and financial risk factors related to component repair or replacement. In the current competitive marketplace, extending the life of existing structures and components has become increasingly important in minimizing the total cost of ownership.

There are many factors that affect plant aging. We provide Fitness-For-Service (FFS) evaluations to demonstrate the structural integrity on tanks, vessels, silos and other process equipment. Our evaluations, based on API-579/ ASME FFS-1 and other specifications, are used to make run/ repair/ replace decisions. These evaluations ensure that pressurized equipment containing flaws which have been identified by inspection can continue to operate. Assessments include:

  • Fracture mechanics and fatigue life assessment
  • General and local corrosion
  • Bulges and out-of-roundness
  • Tank settlement
  • Mechanical vibration
  • Creep & creep fatigue for equipment operating at elevated temperature
  • NDE – Inspection and analysis for Flaws/ Cracks
  • Determining failure modes
  • Fatigue of welded joints

Codes and standards for pressurized equipment provide rules for the design, fabrication, inspection, and testing of new pressure vessels, piping systems, and storage tanks include:

  • ASME B&PV Code, Section VIII, Division 1 – Rules for Construction of Pressure Vessels
  • ASME B&PV Code, Section VIII Division 2 – Alternative Rules for Construction
  • ASME B&PV 31.3 – ASME Code for Process Piping
  • ASME B&PV 31.1 – ASME Code for Power Piping
  • ASME Section XI – Rules for In-Service Inspection of Nuclear Power Plant Components
  • API 650 – Welded Steel Tanks for Oil Storage
  • API 620 – Design & Construction of Welded Low Pressure Storage Tanks
  • BS 5500 – British Standard for Unfired Fusion Welded Pressure Vessels
  • EJMA – Standards of the Expansion Joint Manufacturers Association

However, some of these Codes do not address the fact that such equipment may degrade while in service, and that deficiencies due to degradation, or original fabrication defects may be found during subsequent inspections of in-service components.

Core asset failure can have far reaching consequences, which impact reputation, scheduling, and the bottom line. Fitness for Service evaluations often result in lower maintenance & operating costs as well as improved plant safety.
Read our article in Stainless Steel World. (PDF)

See also our List of Publications.

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