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Fitness for Service

TWI has a long history in the area of fitness-for-service (FFS) and flaw assessment, having been at the forefront of the development and experimental validation of modern FFS methods.

Fitness for Service (FFS) is a standard and best practice used in industries, including the oil and gas industry to determine the fitness of in-service equipment for continued use.

FFS engineers can operate across the full lifecycle of a part, from equipment design to assessing operating conditions, lifecycle extension, and end-of-life decommissioning and recycling.

Fitness-for-Service Support with TWI

TWI’s experts are highly experienced in the development and application of FFS assessment techniques, particularly for the avoidance of brittle and ductile fracture and also general and local metal loss. We can help solve problems that may arise throughout the lifecycle of a component, minimising risk and cost.

Our staff are actively involved in the ongoing research and development of industry standards such as British Standard BS 7910, ‘Guide on methods for assessing the acceptability of flaws in metallic structures,’ API Fitness-for-Service: API 579-1/ASME FFS-, and the UK nuclear industry’s fracture assessment code R6, ‘Assessment of the integrity of structures containing defects.’

Through established multidisciplinary teams, with specialist knowledge in areas of  fracture mechanicsfatiguefinite element analysis, materials, inspection and welding, TWI is able to provide industry-leading services to our international network of Industrial Member companies. We have carried out FFS assessments on pressure vessels, slug catchers, storage tanks, pipelines, piping system and high-temperature equipment in accordance with industry-accepted standards.

Bespoke Services and Training

TWI's wide-ranging expertise is regularly used to develop non-standard testing and assessment methodologies, conforming to the API 579/ASME FFS-1 Level 3 classification. This capability allows us to take on and solve problems where non-standard geometry, unusual loading, or exotic materials mean that standard FFS approaches are unsuitable.

TWI's expert staff are also available to conduct FFS training, either through our in-house training school or as a bespoke programme, tailored to the needs of individual clients.

Case Studies

Find out more about fitness for service at TWI:

Core Research Programme (CRP) and Joint Industry Projects (JIP)

Core Research

Each year the TWI Core Research Programme (CRP) addresses challenges on behalf of our Industrial Members as well as developing specific technologies and processes. Each of the projects under the CRP is focussed on engineering, materials or manufacturing technologies.

Find out more here

Joint Industry Projects

TWI also conducts Joint Industry Projects (JIPs) that bring together groups of Industrial Members to share the cost of research activities in areas of mutual industrial interest, gaining exclusive access to the outcomes. These projects cover a broad range of topics.

Find out more here

When Are FFS Assessments Used?

Fitness-for-service (FFS) assessments evaluate the structural integrity of components and their suitability for continuous service. Procedures such as BS 7910:2013, API 579/ASME FFS-1, ASME B31G, DNV-OS-F101 and FITNET enable the integrity of critical pressure components and welded structures to be assessed against different failure modes, using a validated engineering approach.

As such, an FFS evaluation provides a quantitative measure of the structural integrity of a component containing flaws. Standards used to carry out these assessments provide guidelines which can be used to make run-repair-replace decisions, assisting plant management in identifying appropriate mitigation actions to ensure that the component can be operated safely.

The method can be used to support design, fabrication, operation, change of service, and life extension programmes, and is employed across a wide range of industries, including power generation,  oil and gas, chemical processing and aerospace. Assessments of this type are widely used as part of the plant lifetime management process, to confidently increase availability, reliability, efficiency and safety.

Any unplanned shutdown of a manufacturing or process plant is expensive in terms of both loss of production and the manpower required to solve a particular mechanical integrity issue. Fitness-for-service assessments, especially at the lower ‘screening assessment’ levels, can quickly determine if equipment is safe for immediate return to service. Higher levels of assessment can be complex and time-consuming but still generally require less time than the ordering, supply and commissioning of replacement equipment.

Fitness-for-Service Software

TWI Software offers software to assist with fitness-for-service assessments, these include:

IntegriWISE™ – This software allows for the assessment of the integrity of storage tanks, pipelines, pressure vessels, boilers and high temperature equipment. It assesses damage mechanisms and creating ‘what if’ scenarios. To find out more about IntegriWISE™ click here.

CrackWISE® - This software helps you ensure the continued safe operation of pipelines, structures and pressure equipment by evaluating cracks and crack like flaws. To find out more about CrackWISE® click here.

RiskWISE – This integrity management software is used on process plants, boilers and pipelines to process large quantities of data related to risk-based inspection techniques. To find out more about RiskWISE click here.

Why is Fitness-for-Service Important?

Fitness-for-Service can be defined as being high or low level, with both being important in their own right.

Lower level assessments (such as screening assessments) can show if equipment is fit for continued operation when limited data is available – saving both time and money on repairing or replacing equipment.

Higher level assessments use more data and therefore cost more money than lower level assessments, however they offer a greater level of certainty, which is vital for assessing critical components.

All levels of a Fitness-for-Service assessment are used to increase asset availability, reliability, efficiency and safety. 

Benefits

Fitness-for-Service assessments provide several important benefits for asset owners, including:

  • Support design, fabrication and operation
  • Plant life management
  • Improve equipment availability and reduce downtimes
  • Reduce unnecessary and costly repair or replacement
  • Optimise maintenance and inspection scheduling
  • Improve equipment safety
  • Determine equipment residual life
  • Integrate lessons learnt from previous equipment failures
  • Create life extension programmes
  • Allows for re-rating or operation change

Applications

Fitness-for-Service applications include:

For more information, please email contactus@twi.co.uk.

 

For more information please email:


contactus@twi.co.uk