Reasons for stainless steel pipe fracture
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This post was last edited by CR12 on 2023-1-29 07:53. It was a relatively large project that the company worked on a few years ago; however, it failed to get up and running on the client’s end for various reasons. Debugging began last month, and during trial operation it was found that several of the accompanying condensers had severe leakage issues; some of them were even completely broken at the weld points and could not be repaired. According to colleagues’ recollection, after completion, a pressure test at 0.3 Mpa was conducted; less than 0.1 Mpa of pressure drop occurred over the course of one night. Pressure tests were also carried out during installation at the customer’s site, and no issues were found. (201 stainless steel welded pipe, 38*2) Since I have built the same type of condenser before and there were no problems, I still haven’t figured out whether it’s an issue with the material choice or with the quality of the material itself.
It has something to do with the medium; generally, when it comes to heat exchange with water or steam, the pipes are usually made of 304 or 316 material. This is just my personal opinion
Haven’t used it yet... just kept it with the client for two years
There is still a problem with the saving process. After pressure testing, the moisture inside the tube bundle must be removed; otherwise corrosion will occur, and in severe cases stress corrosion cracking may result from the stress.
Regarding the analysis of the previous image, bro – based on your description, the probability of stress fracture is quite high
It is recommended that the poster check whether the chloride ion level is above the acceptable limit. Under the combined effect of tensile stress, specific temperatures, and high concentrations of corrosive chloride ions, cracks originate on the outer surface of heat exchange tubes with many defects; these cracks then continue to grow, leading to stress corrosion fracture in a relatively short period of time.
201 contains a high amount of manganese, making it prone to rusting. Basically, it cannot compare with 304 in terms of nickel and chromium content, and is mostly used for decoration. Industry still needs 304. It also depends on the operating conditions.
Use 201 less often; at least use 304
Previously, 12mm carbon steel tube sheets plus 201 heat exchange tubes were used, and there were no problems. This time, 6mm 201 tube sheets along with 201 heat exchange tubes are being used – could this be related to the tube sheets?