Issues with the maintenance and inspection of heat exchangers?
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This post was last edited by wei604213406 on 2018-10-26 at 09:36. The heat exchanger is classified as a type 1 pressure vessel, with circulating water as the medium in its shell side. Now, it is necessary to replace the diameter-changing section on the shell side of this device (referenced as number 40 on the drawings). Since multi-chamber pressure vessels are manufactured based on different pressure levels, is it required that a special equipment inspection agency conduct on-site supervision?
Since it is a Class I container, inspection is mandatory. This is the same as the jacketed container; the design can be considered separately, but supervision is carried out based on its classification as a whole.
Heat exchangers are classified as Category 1 pressure vessels; therefore, the highest category applicable to the tube side should be used. The highest category for the shell side is also Category 1 (please verify the shell side parameters), or it may not be classified at all. So, if no classification is applied to the shell side, no inspection is required ； If the shell side is also of that type, it must be monitored and inspected.
It is time to replace and repair the shell side – is supervision required?
The shell side uses circulating water, which isn’t sufficient
No supervision is required. Because, from the shell side alone, it does not belong to pressure vessels. Additionally, it should be noted that even for pressure vessels, major repairs do not necessarily require supervision. According to Article 6.1.2.2 of the Pressure Vessel Regulations, major repairs involving the replacement, reshaping, patching of main pressure-bearing components, as well as the rewelding or bonding of shell butt joints, and which require pressure testing or post-weld heat treatment, are not subject to such supervision
For a certain type of pressure vessel, it is necessary to submit it to a special equipment inspection agency for on-site inspection; generally, no one shows up after the submission, and it is sufficient to submit the inspection report for registration.