An investigation into excessive vibration in a small-bore pipe revealed that one end of the pipe was supported on a beam that was also connected to a large-bore pipe experiencing elevated vibration. This structural connection likely transmitted vibration from the large-bore pipe to the small-bore piping system. Additionally, loose bolting was observed on equipment located at the opposite end of the small-bore pipe. This mechanical looseness contributed to elevated vibration levels at that end as well. The combination of transmitted vibration and insufficient mechanical restraint resulted in excessive overall vibration of the small-bore pipe.