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TWI enhances on-stream inspection service

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

Connect, no.81, November-December 1996

On-stream inspections by TWI using specialised NDT techniques are helping a major oil company make cost-effective decisions on continued operation versus repair or replacement.

Working overseas, TWI has successfully completed a series of on-stream ultrasonic inspections of a weld section in a thick-walled pressure vessel operating at elevated temperature.

The automated ultrasonic testing procedures used were developed by TWI over a period of several years. Initially, only the time-of-flight diffraction (TOFD) technique was applied using TWI's Zipscan III flaw detector. Subsequently, the inspection was enhanced using the Force Institutes' P-Scan system for pulse-echo inspection.

This year, TWI has further improved its elevated temperature TOFD capability by adding a state-of-the-art AEA Sonomatic Microplus system and developing, in-house, a simple high temperature TOFD scanner for surfaces which are typically around 250 degrees C.

Using computerised ultrasonic techniques has meant that the data acquired are highly repeatable from one in-service inspection to another. Also, the use of complementary techniques provides the optimum combination of data for flaw detection, characterisation and sizing.

The purpose of these periodic on-stream inspections is to assure mechanical integrity and allow better planning and scheduling for repair, or if necessary, replacement. Results are used in fitness-for-service evaluations, enabling the company to continue operating the equipment safely and reliably and, where feasible, defer any repair/replacement costs.

For further information contact Mark Kirby at TWI.

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