Fitness for Service

Fitness for Service

TCR undertakes

Fitness For Service (FFS)

Assessment based on Level 2 BS 7910 standards and API 579. Our fracture mechanics methodology and its application have been successfully proven worldwide across industries, including nuclear pressure vessels to high consequence items in the exploration, refining, petrochemical and construction industry.

A process, plant, and equipment are often exposed to corrosive environments and/or elevated temperatures. Under these conditions, the material used in the equipment can degrade or age with time. When important equipment such as pressure vessels, piping, and storage tanks become older, the plant operator must decide if they can continue to operate safely and reliably to avoid injuries to personnel and public, damage the environment, and cause unexpected shutdowns.

Fitness for service assessment

procedures provide the means for the plant operator to make appropriate decisions on established engineering principles.

Fitness for service assessment is a multidisciplinary engineering analysis that ensures all process and plant equipment such as pressure vessels, piping, and tanks operate safely and reliably for the desired period of operation and until the next turnaround or planned shutdown occurs in the future. ASME, API, BS 5500 & other recognized design codes provide rules/guidelines for a general procedure for assessing fitness for service. This assessment procedure evaluates the remaining strength of the equipment in its current state that may have degraded from its original condition. Common degradation mechanisms include corrosion, localized corrosion, pitting and crevice corrosion, hydrogen attack, embrittlement, fatigue, high-temperature creep, and mechanical distortion.

Fitness for Service
TCR Advanced Approach

Fitness for Service Assessment uses Analytical Methods to Evaluate Flaws, Damage and Material Aging based on:

  • Stress Analysis may be performed using Standard Handbook or Design Code Formulas or by means of Finite Element Analysis (FEA). With the advent of modern computer technology, the use of FEA is quite common.
  • Fitness for Service Assessment requires both, knowledge of past operating conditions and a forecast of future operating conditions.
  • Non-Destructive Examination (NDE): NDE is used to locate, size and characterize flaws
  • Material Properties: The material properties include information on material damage mechanisms and behavior in the service environment, especially on the effects of corrosion and temperature
Common Reasons for Assessing The Fitness for Service for Equipments Include:
  • Discovery Of A Flaw Such As A Locally Thin Area (LTA) or Crack
  • Failure to Meet Current Design Standards
  • Plans for Operating Under More Severe Conditions than Originally Expected
Outcome of Fitness for Service Assessment
  • ​​​Decision to Run, Alter, Repair, Monitor, or Replace the Equipment
  • Guidance on Inspection Interval for the Equipment