Fitness for Service (FFS)

Fitness for service (FFS) (API RP 579) evaluates the remaining strength of the equipment in its current condition, which may be degraded from its original conditions.

Fitness for service (FFS) (API RP 579) evaluates the remaining strength of the equipment in its current condition, which may be degraded from its original conditions. Common degradation mechanisms include corrosion, localized corrosion, pitting and crevice corrosion, hydrogen attack, embrittlement, fatigue, high-temperature creep, stress corrosion cracking and mechanical distortion. Fitness for Service may be required, because the equipment may:

• Contain flaws such as Locally Thin Areas [LTAs] of Cracks
• Not meet current Design Standards
• Operate under more severe conditions than originally expected.