Teletest® Long range UT inspection trials for Caltex, Indonesia

The road crossings inspected for ARCO and BP Amoco in Alaska described in another case history were sleeved. Work for Caltex, carried out by TWI's wholly owned subsidiary, Plant Integrity Ltd (P i) under sub-contract to International Refinery Services of Singapore, included tests on pipes buried directly in the ground. It was found that, whilst adherent earth and corrosion products attenuated the Teletest® signals, ultrasound could be transmitted 10m or more. The attenuation made interpretation difficult. However, it was possible to isolate flaws at the reporting level, once the problem had been identified. An interesting aspect of this work is that, in some cases, the pipe temperature exceeded 100°C. This had no adverse effect on the Teletest® performance.