Leakage issues in catalytic cracking unit trains
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Leakage issues in the continuous drain lines of catalytic cracking units. There are frequent leaks in the continuous drain lines of various units. Are there similar problems in other units as well? How are they resolved?
If the leakage location on the manifold pipe is near the pipeline after the shut-off valve, it may be caused by erosive vaporization. Consider adding stepped pressure-reducing orifice plates; we have not encountered such a situation before.
We have never encountered this kind of problem either; is it always a leak in one particular area? Is it that the spacing is too large, resulting in erosion, or is there a problem with the material?
The phenomenon of sequential erosion, combined with high temperatures and prolonged use of the pipelines, can lead to leaks.
Where does the leakage occur? In my case, leaks usually happen at the elbows
At the 45° elbows of our process piping, erosion-induced leakage points frequently occur. There was no other choice; during this maintenance, we replaced them with thick-walled socket weld elbows made of a higher-grade material
I remember that we both had double-valve setups; it seems that the leakage you mentioned never occurred. I’ll check the valve data for you another day!
Erosion is severe at the elbows; after a leak occurs, a layer is welded on externally (refer to the method of applying patches over leak points). Replacement will be carried out during major maintenance. When the leak is minor, this procedure is relatively easy to perform
The reason is the coexistence of water vapor; vaporization erosion leads to 1 the need for an upgraded pipeline material or the use of thick-walled elbows, and 2 the installation of pressure reduction orifice plates after the elbows