API 579 Fitness‑for‑Service Assessment Services

API 579 Fitness‑for‑Service Assessment (FFS) is the fastest way to turn inspection findings into a clear decision: can the equipment remain in service, does it need rerating, or should it be repaired now or at the next turnaround. At Inspection 4 Industry LLC (I4I) and I4I Academy, we perform Fitness‑For‑Service evaluations in accordance with API 579‑1 / ASME FFS‑1 and issue a complete engineering report that you can use for integrity decisions, operations planning, and management review. Our API 579 Fitness‑for‑Service Assessment (FFS) service is built for real refinery and oil & gas equipment—where corrosion, cracking, distortion, hydrogen damage, fire exposure, mechanical damage, creep, fatigue, and ratcheting are part of normal life.

API 579 Fitness‑for‑Service Assessment (FFS) Deliverables

Every API 579 Fitness‑for‑Service Assessment (FFS) we deliver is a decision-ready package—not a generic memo and not a coaching exercise. You provide the inspection/NDE results and operating basis, and Inspection 4 Industry LLC performs the applicable API 579 Part(s) and Level(s) and issues the report with results.

Your final report package typically includes:

The applicable API 579 Part(s) and the assessment Level used (Level 1 / Level 2 / Level 3)
Clear conclusion: Fit for service / Not fit for service at the evaluated operating conditions
Rerated limits when required (for example, reduced allowable pressure and/or temperature limitation)
Practical integrity actions: repair now, repair at next turnaround, or monitor and run with defined scope
A monitoring/inspection basis aligned to the controlling damage mechanism
Traceable inputs, assumptions, calculations, and an organized report structure suitable for internal review

How Inspection 4 Industry LLC Performs an API 579 Fitness‑for‑Service Assessment (FFS)

A proper FFS project starts with disciplined classification and ends with a defensible decision. Once you submit your data package, Inspection 4 Industry LLC runs the API 579 Fitness‑for‑Service Assessment (FFS) using the correct Part(s) and Level(s), and we deliver a complete report you can act on.

In practice, most projects begin after one of these triggers:

Turnaround inspection finds unexpected damage or indications
RBI-driven inspection reveals thinning/pitting beyond expectations
A process upset, fire exposure, or abnormal event raises integrity concern
NDE reports crack-like indications and operations needs a run/repair decision fast

If one Part is not enough, we do not force a single method. We integrate multiple Parts when required and issue one coherent conclusion that identifies the controlling mechanism and controlling operating limit.

API 579 Fitness‑for‑Service Assessment (FFS) Services by Part

Below is how Inspection 4 Industry LLC performs assessments aligned with each API 579 Part. Each section is written in “equipment language” so it reads like your plant, not a textbook.

Part 1 — Damage Identification and Assessment Planning

Many real findings do not arrive neatly labeled. Part 1 is where the integrity decision begins: what kind of condition is this, how did it likely originate, and is it likely to progress under actual service conditions? This step prevents wasted time and wrong conclusions later.

Consider a crude unit turnaround where UT mapping on a fractionator shell shows broad thinning, a small localized low-thickness region near an inlet nozzle, and a linear indication reported by PAUT at a nozzle weld. Inspection 4 Industry LLC classifies these conditions correctly and sets the assessment plan so the final report evaluates what truly controls risk, instead of averaging everything into a misleading result.

Part 2 — Fitness‑For‑Service Engineering Assessment Procedure

Part 2 is the backbone of how an assessment is organized: applicability, required data, assessment technique and acceptance criteria, remaining life approach (where provided), remediation options, monitoring expectations, and documentation. Inspection 4 Industry LLC follows this structure so your final report is complete, reviewable, and defendable.

A common example is an overhead reflux accumulator vessel where inspection reveals more than one mechanism in the same circuit: general thinning, localized thinning around a nozzle, and scattered pitting. We structure the project correctly, apply the required Parts, and issue one integrated report that answers what operations needs: fit/not fit today, any rerated limits, and whether it can run to the next shutdown with defined monitoring—or must be repaired before continuation.

Part 3 — Brittle Fracture Assessment

Brittle fracture is not a corrosion-rate question; it’s a fracture-risk question driven by metal temperature, material behavior, stress, and flaws. Inspection 4 Industry LLC performs Part 3 brittle fracture assessments when low temperature events, start-ups, shutdowns, or unexpected cooling create concern about safe operation.

For example, during a winter start-up a light ends receiver or a cold-side exchanger channel experiences a metal temperature excursion below what the unit expected. The site wants a restart decision that can stand up to scrutiny. We execute the Part 3 evaluation route using the available design basis, operating envelope, and relevant inspection findings, then issue a report stating whether the component is acceptable at the evaluated conditions or whether restrictions/rerating actions are required.

Part 4 — General Metal Loss Assessment

General metal loss is refinery reality: broad wall thinning from long-term corrosion or erosion. Inspection 4 Industry LLC performs Part 4 assessments when thinning is general in nature and the question is whether remaining thickness supports continued operation at current conditions, or whether rerating is required.

Think of a vacuum column bottom section with widespread thinning across a large shell area after years of high-severity service. Management wants a decision: keep running to turnaround, rerate, or repair now. We apply Part 4 using your thickness data (grids or scans) and operating basis and issue a report that clearly states acceptability and, when required, defines rerated operating limits to safely reach the next planned outage.

Part 5 — Local Metal Loss Assessment

Local metal loss is where average thickness can look acceptable but a localized region controls integrity. Inspection 4 Industry LLC performs Part 5 assessments using detailed thickness profiles when local thin areas or groove-like features govern the decision.

A refinery example is localized under-deposit corrosion in a crude overhead circuit creating a concentrated low-thickness region near a nozzle or discontinuity. The key decision is whether it is acceptable to continue until the next shutdown and what limits apply. We characterize the local region correctly, execute the Part 5 checks, and deliver a report stating fit/not fit, any rerated limits, and whether repair should be immediate or can be planned for the turnaround with monitoring.

Part 6 — Pitting Corrosion Assessment

Pitting is not “just thinning.” A small number of deep pits can control integrity even when average thickness looks fine. Inspection 4 Industry LLC performs Part 6 pitting corrosion assessments for localized and widespread pitting, including cases where pitting activity must be considered relative to a future inspection date.

A very common oil & gas case is a cooling-water exchanger channel head or water box with scattered but deep pits. The plant needs more than “watch it.” We evaluate pitting severity using the Part 6 methodology and issue a report that answers two operational questions: is it acceptable now, and will it remain acceptable until the planned next inspection—along with a monitoring interval recommendation that matches the risk.

Part 7 — Hydrogen Blistering, HIC, and SOHIC Assessment

Hydrogen damage can drive overly conservative decisions if it is not treated correctly. Inspection 4 Industry LLC performs Part 7 assessments for hydrogen blistering, HIC, and SOHIC, including cases near welds and discontinuities, and we apply the proper assessment route when the evaluation must link to other Parts.

In refinery service, a realistic scenario is a sour water stripper drum or hydrotreater-related circuit where UT scanning identifies HIC-type indications near a weld and blister-like features in a localized region. Operations wants to know if the equipment can safely run to the next turnaround and what monitoring is necessary. We perform the Part 7 assessment pathway and deliver a report that states acceptability, any required rerating or repair actions, and a monitoring plan aligned to the hydrogen damage mechanism.

Part 8 — Weld Misalignment and Shell Distortions Assessment

Settlement, out-of-roundness, bulges, peaking, and misalignment can become integrity issues even when thickness is fine. Inspection 4 Industry LLC performs Part 8 assessments when geometry itself is the concern and must be evaluated for acceptability in pressurized service.

A familiar refinery case is a tall fractionation column that develops measurable ovality due to foundation movement, or a localized bulge after an internal event. You provide dimensional survey data or targeted measurements. We apply Part 8 and issue a report stating whether the distortion is acceptable at current operating conditions, whether rerating is required, and whether correction or reinforcement should be executed immediately or can be planned for the next outage.

Part 9 — Crack‑Like Flaw Assessment

Cracks require a different approach than metal loss. Inspection 4 Industry LLC performs Part 9 crack-like flaw assessments when NDE identifies planar indications, crack-like features, or flaw shapes that must be treated as crack-like to determine safe operation.

A typical refinery case is a crack-like indication found by PAUT/TOFD at a nozzle-to-shell weld on an FCC main fractionator or at a weld in an amine circuit with high stress concentration and cyclic operation. The unit needs a decision: can it run to the next planned shutdown with monitoring, or is immediate repair mandatory? We execute the Part 9 assessment at the applicable level and deliver a report that states fit/not fit, any operating limitations, and the recommended integrity action and timing.

Part 10 — Creep Assessment for High‑Temperature Service

Creep is time-dependent damage and becomes a remaining-life management issue in high-temperature service. Inspection 4 Industry LLC performs Part 10 assessments when components operate in the creep range and remaining life must be evaluated for continued safe operation.

A classic refinery scenario is fired heater outlet piping or hot headers with long-term exposure at elevated temperature, sometimes combined with operational cycling. The business decision is whether the circuit can safely meet the next run length and what inspection interval is necessary. We perform the Part 10 remaining-life evaluation and deliver a report that provides a practical integrity plan: continue with defined monitoring, rerate to extend life, or schedule repair/replacement at a defined outage to prevent a run-ending failure.

Part 11 — Fire Damage Assessment

Fire exposure creates urgent restart decisions. Inspection 4 Industry LLC performs Part 11 fire damage assessments for equipment exposed to fire or overheating from a process upset, including evaluation of distortion, potential property degradation, and the resulting integrity decision.

Imagine a pump seal fire or localized hydrocarbon pool fire that exposes nearby piping and a small vessel such as an overhead accumulator or separator. The site needs a defendable answer before restart. You provide the event description, exposure area information, and inspection results (dimensional checks, NDE findings, hardness/metallurgical checks if performed). We execute the Part 11 evaluation route and issue a report stating whether the equipment can return to service as-is, whether rerating is required, or whether repair/replacement is mandatory before restart.

Part 12 — Dents, Gouges, and Dent‑Gouge Combination Assessment

Mechanical damage happens during maintenance, lifting, transport, or unexpected impacts. Inspection 4 Industry LLC performs Part 12 assessments for dents, gouges, and combined dent-gouge conditions to determine whether the damaged area is acceptable for continued pressure service and whether fatigue concerns require more detailed evaluation.

An oil & gas example is a gas plant separator or produced-water vessel dented during maintenance with visible surface damage at the dented region. The operator wants a clear decision: keep running until shutdown, repair now, or monitor. We characterize the damage geometry based on your measurement data, apply the Part 12 assessment approach, and issue a report that states acceptability, any operating limitations, and repair timing recommendations aligned to the result.

Part 13 — Laminations Assessment

Laminations can appear during UT mapping even when equipment has run for years. Inspection 4 Industry LLC performs Part 13 lamination assessments and applies the Part’s routing logic when laminations behave like other damage types.

A refinery scenario is UT scanning on a vessel shell course—such as a desalter vessel or a drum in corrosive service—where laminations are reported near a seam and close to weld areas. The concern is whether they threaten integrity near discontinuities or could interact under service loads. We perform the Part 13 evaluation and deliver a report stating acceptability, monitoring requirements, and whether repair or replacement planning is required.

Part 14 — Fatigue Damage and Ratcheting Assessment

Fatigue and ratcheting are driven by cycles: start-ups, shutdowns, pressure/temperature swings, and repeated transients. Inspection 4 Industry LLC performs Part 14 assessments when cyclic operation is significant, when ratcheting is suspected, or when cracking indicates fatigue-driven mechanisms may control remaining life.

A refinery example is a compressor discharge circuit or overhead system that sees frequent start-stop operation and thermal swings, where cracking appears near weld toes, attachments, or discontinuities. The site wants to know whether the component can safely continue under the current operating pattern, whether cycle limits or operational changes are needed, or whether repair must be done now. We build the loading/cycle history from available plant data, execute the Part 14 evaluation route, and deliver a report that converts operational cycling into a clear integrity decision.

When More Than One Part Applies

Real equipment often contains more than one damage mechanism. A crude unit overhead receiver can show general thinning, localized thinning, and pitting. A sour circuit can combine hydrogen damage and crack-like indications. A fire event can trigger Part 11, but the controlling condition after inspection might be metal loss, cracking, distortion, or creep. Inspection 4 Industry LLC integrates all applicable Parts into one coherent assessment and one report conclusion that identifies the controlling risk and the controlling operating limit.

Start Your Assessment

If you have an inspection finding and need a defensible decision, send the available inspection and operating basis and request an API 579 Fitness‑for‑Service Assessment (FFS) from Inspection 4 Industry LLC. We will perform the applicable Part(s) and deliver the complete Fitness‑For‑Service report package with results, limits (if any), and clear integrity actions for continued safe operation.

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