Fitness for Service (FFS) – AP 579/ASME FFS-1 determine if your equipment is safe and fit for continued service operation to prevent failures, minimize risk and eliminate costly repairs.

Fitness for Service (FFS) assessment is a multidisciplinary engineering approach used by the oil & gas, power generation, and chemical processing industries for pressure-containing equipment to evaluate its fitness for service. API/ASME Standard API 579/ASME FFS-1 is an international standard for conducting FFS assessments.

With access to global multidisciplinary resources and extensive experience of our highly qualified engineers in the field of FFS, Element can evaluate the integrity and remaining life of a wide range of components, including boiler, HRSG, pressure vessels, chemical reactors, storage tanks, piping systems and pipelines.  From design to decommissioning, our FFS assessment services help you make cost-effective run-repair-replace decisions, select the most appropriate repair options and solve problems that may arise throughout the lifecycle of a component.

API/ASME Standard API 579/ASME FFS-1 methodology 

We routinely conduct FFS assessment according to API/ASME Standard API 579/ASME FFS-1 standard to assess stability and propagation rates of different types of defects which can be found in a component both in design and in-service phases. Our Engaged Experts are qualified to Level 2 and 3 for NDT and metallographic replicas to provide a complete fitness for service API 579/ASME FFS-1 assessment. 

Our Approach to FFS Assessments 

FFS is the best approach to evaluate both damaged kinetics and defects in critical dimensions. Element can perform FFS assessments for components stability using the following steps:

  • Identification, selection, and characterization (position, orientation and size) of component defects relevant from the stability point of view
  • Determination of relevant characteristics of the component material
  • Thermo-mechanical analysis under operating conditions (temperature and strain): normal service, transients, predictable exceptional or even faulted service condition
  • Structural analysis under normal operating conditions aimed at the detection of anomalies (thickness reduction due to corrosion/erosion, subsidence/displacement of supports/anchors, etc.) to evaluate the further use and the need for any corrective actions
  • Design, design verification,  faulted component assessment and requalification

Defects propagation rate evaluation and stability assessment for each operating conditions according to recognized procedures and standards (API 579, BS 7910, DNV, NE R5, NE R6, etc.).

fitness for service (FFS)

Our FFS assessment services

  • Boiler and heat recovery steam generator components (headers, drums, etc.)
  • Piping (water/steam piping, process piping, penstocks, etc.)
  • Turbine (rotors and housing)
  • Other plant components (pressure vessels, valves, pipes, tubulars, furnaces, reactors, heat exchangers, etc.)
fitness for service (ffs)

FFS evaluation of the components of energy production, processes and power plants

Element has a wide range of knowledge including structural analysis, materials science, and control techniques to perform FFS evaluation and reliability assessments of the components for energy production, process and power plants.

Plant components may contain defects during manufacturing processes and service life, which reduces the initial degree of "safety" and "integrity" with which it was designed.

Energy production, process and power plants such as nuclear power plants (NPP) and Hydro Power Plants, which often use complex systems, are located in adverse environments and interact significantly with the population residing in the neighboring territories and with other infrastructures such as roads and railways. For these reasons, safety aspects play a fundamental role in all phases of their life cycle; design, fabrication, construction, service, operation and decommissioning. 

We can assess component stability according to internationally recognized procedures and regulations, and not only refer to actual defect or material conditions but also consider their future evolution in expected service conditions.


Our team of over 6,700 Engaged Experts in North America, Europe, The Middle East, Australia, Asia and Africa are ready to help you.