I would like to inquire about the service life of carbon steel pipe bundles in refineries
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I would like to know about the service life of carbon steel pipe bundles in the refineries everyone is in – are they replaced when blockages of over 10% are detected during maintenance, or when severe corrosion is found during inspections? Or should it be replaced directly once a certain usage period has passed, even if there is no leakage? Currently, it has been observed that some carbon steel tube bundles start to develop internal leaks during operation after more than two maintenance cycles.
It needs to be repaired! Redo it, taking material standards, material data sheets, and manufacturing damage levels into account!
1. The lifespan of the tube bundle is closely related to the specific operating conditions of the user, with the corrosion properties of the medium being the most typical factor. 2. The topic of this section overlooks the key factors related to corrosion; even if the statistical service life of the tubes is determined, it has little practical value for specific cases. 3. Some maintenance manuals recommend using a 20% blockage rate as a criterion for deciding whether to replace the tubes, but this approach is suitable only for the early stages when the operation cycle was short. It is no longer appropriate to use this criterion in today’s context where longer operation cycles are required. 4. It’s not that tubes with a 20% blockage rate can no longer be used; rather, large-scale tube leaks are no longer caused by manufacturing defects but rather by corrosion ； The damaged pipes that have leaks are affected, and even the pipes that do not leak are damaged, making it difficult for them to continue operating for an extended period of time. 5. Users should maintain records of the piping systems they use, identify the patterns of corrosion, and then determine a reasonable service life based on the operating cycle. 6. Of course, it’s another matter if users can accept the mode of replacing the tube bundle during operation.
The undamaged tube bundles are subjected to pressure testing; if they pass the test, there is no need to replace them. In addition, the service life of each heat exchanger’s tube bundle should be tracked in order to determine whether replacement is necessary
Thank you for the reply. Keeping track of the usage cycle of the leaky tube bundles is a very important management task ； Since the refinery has only operated for two cycles, some of the tube bundles made of carbon steel are leaking for the first time, and there is limited operational experience data available ； I’d like to refer to the operational experience data from other similar units. It is indeed crucial to identify the unit’s corrosion patterns and determine a reasonable service life for the tube bundles based on the different compositions of the crude oil processed, and this is a long-term task.