Could a small flame from the lagging box, even if directed at the intrados, have raised the temperature to 950°C?
Answer It was clearly essential to demonstrate that an external flame could heat the intrados of the elbow to 950°C whilst the superheated cyclohexane was circulating. As the Court was not prepared to check the 8″ line hypothesis, the Insurers arranged independent tests at a commercial fire-testing establishment (Yarsley Laboratories). These were reported formally to the Court and the test report introduced in evidence. At that time it was felt that demonstrating the principle would be sufficient; accordingly a test rig was constructed in which the 8″ pipe run was fabricated to one quarter scale in stainless steel pipe. The test fluid was water recirculating by pump through the test region from a supply reservoir to a receiver. The flow rate was also scaled and the water temperature was maintained close to 100°C – thus emulating the prototype. Burners directed flames at the intrados and red heat was achieved there in the flowing system. Subsequently there was criticism that the test co
