Home › Forums › Coking › Design and Reliability › Cokedrums, Structure, Inspection › Drums › Abnormal sound in coke drum after switchover This topic contains 0 replies, has 1 voice, and was last updated by Freddy Martinez 10 years, 1 month ago. Author Posts August 24, 2012 at 5:28 am #1820 Freddy MartinezParticipant We r facing a new problem in our coker. After every switch over we observed some abnormal metallic sound coming from the Drum which is taken on line. That too from. 7 to 8 m height from the BUD. Kindly suggest me why this sound is coming and wat could be done to avoid such sounds. Author Posts You must be logged in to reply to this topic.