Regarding the thickness of the segmented partition
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Dear sea friends, I have a question for everyone. I would like to know whether it is necessary to take into account a corrosion margin for the partition plates in multi-pass heat exchangers
According to GB151, for non-compressive components such as tie rods, spacers, baffle plates, and support plates, a corrosion allowance is generally not considered.
I just saw the draft for feedback on GB151-2012, which specifies that a corrosion margin must be considered on both sides of the split diaphragm. . Let’s wait until the official version is out and then take another look. . . Just at the moment, does the partition belong to the compressed elements?
The components without corrosion allowance are all the internal elements of the tube bundle, and the service life of the tube bundle is significantly shorter than that of the equipment! I think a corrosion allowance still needs to be considered for the tube bank partition! ! Because the tube box is not a vulnerable component!
GB151-99 stipulates this, and the new version of GB151 may modify it.
I don’t think it’s necessary to consider this, as the pressure difference between the two sides is generally not significant. GB151 provides a recommended thickness, and this thickness usually meets the requirements regarding corrosion and pressure differences. Only in cases where the pressure difference is relatively large is the thickness of the split diaphragm determined based on that pressure difference; in such situations, the impact of corrosion must be taken into account.
The heat exchanger design manual states that no additional corrosion allowance is required. . .
There is a recommended thickness specified for 151; this recommended thickness takes corrosion into account. Using this recommended value generally solves the problem. The partitions are not under compressive stress, so it is sufficient to ensure they meet the requirements regarding strength and corrosion-induced wear. Problems with partitions in heat exchangers are quite rare.
Teacher Zhang Yingkai said that some of the partitions are dented, and it is necessary to take into account the pressure differences at various stages. If this information is not available, one can use the pressure difference between the inlet and outlet of the tube box as a reference for safety purposes.
The split diaphragm groove requires consideration of corrosion margin on both sides
In a corrosive medium, it should be taken into account that,