Fitness-for-service assessment

What it covers

Fitness-for-service assessment decides whether equipment with a known flaw or degradation can keep operating safely, and for how long. It covers metal loss and corrosion, pitting, blisters and laminations, weld misalignment, crack-like flaws, creep, fire damage and dents. The engineer takes inspection data, applies a Level 1, 2 or 3 assessment, and produces a documented run, repair or replace decision with a remaining-life estimate and a re-inspection interval.

When you need it

You need a fitness-for-service assessment when an inspection finds damage that falls outside the original design or the simple acceptance tables, when you want to extend the life of ageing plant, or when you need to justify continued operation to a regulator or insurer. It is the analytical alternative to an immediate repair or shutdown.

Standards, codes and tools

Commonly used tools: Signal Fitness-for-Service, Ansys, Abaqus.

What to look for

Look for an engineer who has run Level 2 and Level 3 assessments, not only the Level 1 tables, and who can combine the assessment with the inspection and the original design code. Ask for examples of the damage mechanism you are facing, because corrosion, cracking and creep need different methods. The deliverable should give you a defensible decision and a re-inspection date, not just a number.

Fitness-for-service assessment by city

Common questions

Further reading