The tube sheet has started to act cute
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A reboiler that has been in use for over 5 years was subjected to a pressure test, and holes were found in the tube sheet; the diameter of these holes is approximately 3 millimeters. I would appreciate it if the experienced members of this forum could help analyze the cause
The media will intermix; are there no signs?
Judging from the photos, the tube sheet shows almost no corrosion, with only one leak point; this is likely due to welding defects, such as pre-existing non-through cracks, pores, or slag inclusions that became through under the long-term effects of pressure and temperature loads. Just perform patch welding.
How is the tube sheet manufacturing process inspected?
It may be a problem with the tube sheet processing; the defects should be removed, then rewelded, followed by a hydrostatic test.
This post was last edited by wanlirn on 2019-5-26 at 13:21. Is it definitely on the base material of the tube sheet? It’s possible that the hole was drilled off-center; a plug was inserted, and then another layer was welded on the outside. Over time, the weld came apart – our factory has done this before
Clean it, use a surface probe to check for any remaining defects; if none are present, welding repairs can be carried out
We have encountered this issue as well, but it occurred on the circumferential welds. The cause, as analyzed at the time, was two-phase corrosion caused by steam and liquid. We are located in the lower section of the reboiler, where there is no dew point ahead.
If it is a pressure vessel, a series of procedures such as notifying the inspection authority are also required