Session C: Discussion

PAPER 8

Mr P.G. Bolron, GAAA, Prance

1. One interesting conclusion of the studies presented in the Paper is that the length of defect which will produce failure of a pressure tube is several orders of magnitude greater than that which could be detected by inspection techniques which can be applied throughout in service. It seems that inspection in service is intermittent. Have any tests been made to evaluate the time-lag needed for an initially non-detectable defect to reach critical size? What is the frequency of inspection in service,, and what is the process used? How are such defects differentiated from normal leakages from the rolled joints?