Subscribe to our newsletter to receive the latest news and events from TWI:

Subscribe >
Skip to content

Far East fitness-for-purpose check

Back to Pre-1998 Articles Adhesive technology demonstration centre Aged samples lend added credence to safety codes Arc welding Demonstration Centre shows best practice in action Boiler takes the heat in comfort Conductive adhesive for ultrasound catheter cracking-risk-in-steel-pipelines-from-external-hard-zones Engineering critical assessment of pipeline welds Far East fitness-for-purpose check First UK Research Council contract for TWI Friction stir welding of titanium Help with adhesives training Joining demonstration centres in industry Joining Forces success in Belfast Joints take 10 seconds in the microwave LIVEMAN - Advanced joining processes for lightweight vehicle manufacture Making calculations easier 'Mildly sour' environment project saves half a million pounds New standard for weld fracture toughness testing Novel method joins plastic pipes Plastics fume - new findings released Project saves time and money for Amerada Hess Small firms seize no-cost reviews and low-cost trials South East Asia ACFM course Space Shuttle technology transferred to power generation industry Spot the evidence Structural integrity assured for Liverpool Bay Supporting technology on the Indian sub-continent Technology demonstrators show best practice in action Thermomechanical material processing by friction [friction pillar processing] 'Tubestress' measures residual stresses in parts that other equipment cannot reach TWI enhances on-stream inspection service Underwater welding work expands at TWI North Wider recognition for welding inspectors

Far East fitness-for-purpose check

Connect, no.76, May 1996

McDermott SEA Pte Ltd recently called in TWI to carry out a fitness-for-purpose assessment. The subject was a small root undercut detected in an X65 pipeline girth MMA weld made for the Cariogly field off the Malaysian coast.

Initial assessment was carried out using conservative estimates of fracture toughness value and results were reported within one day of receipt of the necessary information. Following discussions with McDermott's clients, the calculations were updated using improved data and measured fracture toughness (CTOD) values.

The work done using the minimum measured CTOD value showed that surface cracks of approximately 2mm deep x 105mm long are not critical. Safety margins of more than 2 on flaw depth and of more than 3.5 (including misalignment effects) on applied stress were determined.

This inexpensive and fast turnaround project demonstrated that the mechanical integrity of the pipeline is unaffected by the presence of a small root undercut throughout its design life.

More information please contact us.

For more information please email: