With the recent resurgence in Oil and Gas production many downstream assets, such as pipelines, refineries, and petrochemical plants are continuing to remain in service beyond their originally envisaged design life. Management of the integrity of these assets presents operators with new challengers. These assets may have existing defects but are uneconomic to replace.
Fitness for service assessment determines if an item of pressure equipment, with a reported defect, is safe to remain in service and for how long.
Rhodes Engineering and Design Limited is accredited by IANZ to perform fitness for service assessment in accordance AS/NZ 3788:2006. We utilise this standard and referenced documents such as ASME/API 579-1 or BS7910 in performing our assessments.
We review examination reports of the defect or defects, perform calculations using advanced analysis tools, and produce a report detailing the suitability of the equipment to remain in service. This report may then be supplied to your accredited site Inspection Body’s Pressure Equipment Inspector to assist in the issuing of a Certificate of Inspection. The Inspector can be reassured as to validity of our findings, as we are an IANZ accredited Inspection Body and these assessment are performed by an engineer certified by IPENZ as a Pressure Equipment Design Verifier.
Level 1 fitness for service calculations, such as general corrosion on cylindrical shells, may be performed by your site Inspectors. However we can assist where more complex (e.g. API-579 Level 2 or 3) calculations are required. Typical examples are:
  • Localised corrosion
  • Corrosion on or adjacent to flanges, nozzles, lugs, pipe supports, etc
  • Fatigue assessment of equipment subject to batch or cyclic operation
  • Equipment in high temperature service
Examples are shown below.

Assessment of corroded stream turbine casing.

Assessment of corrosion adjacent to pipe shoe.