Investigating The Failure of The Sliding ladder of Mogas Tank No.703 at Elroyan Station

Abstract

This study is aimed to cover and highlight the causes of failure of the sliding ladder and the rollers of the floating roof tank No.703 at Royan station of Sudanese Petroleum Pipe Line Company (SPPC), and to suggest remedy measurements. The sliding ladder was completely damaged for unknown reasons, this occurred while the floating roof was moving up. The plates that hold the seal between the roof of the tank and the shell courses to avoid losses due to vapor or leakages were harmed too , finally the railway guide of the rollers was found to be bent. The same failure occurred on tank No.704 which indicate that a real problem exists which needed to be investigated. This was the first time for such problem to occur in the above mentioned company in spite of having floating roof tanks erected since 1977 and they are functioning properly. The damaged parts of the floating roofs were constructed locally by Sudanese company while foreign contractors erected others. Similar design to this damaged tank in railway guides, differs in the roller size are used to store the same product was erected by Romanians is functioning properly. An analysis to the ladder and the rollers were carried out to investigate the possible causes of that failure. The cause of failure was attributed to the material of the roller and it is suggested to replace the aluminum rollers by steel fabricated rollers and to use the same ladder with the same operational conditions at Elroyan station with some precautions for the roof level in operation.