There are 5 numbers of coke chambers in the Dubbs Coking unit of Digboi Refinery. These coke chambers are meant for producing petroleum coke from the residual fraction of the petroleum crude. The coke chambers have been in operation for last 60 years and due to repeated thermal cycles some of the coke chambers have developed noticeable bulges. The chambers are constructed of ASTM A 70 steel as per the then prevailing standard of 1934 and no radiography was done at that time. The operating temperature is 468 degree centigrade with a 24 hour cyclic loading. To determine the extent of deterioration during service and future serviceability, investigation was carried out with the he help of PDIL and IOC R&D Centre. The tests carried out included insitu- metallography, ultrasonic, radiography, etc. the paper deals with investigation carried out and the results of this investigation.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 2, pages 1035 - 1040 Publisher:Ashgate Publishing Company
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