Regarding the surfacing of reinforcement pipes
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The inner hole of the reinforcement tube needs to be surfaced with stainless steel. Due to the surfacing defects, those defective areas were machined off. In order to remove all the defects, it was not possible to enlarge the inner hole of the reinforcement tube by 4 mm, which would have meant reducing the wall thickness by 2 mm. However, the areas that were machined thin as a result of these defects are not located within the effective reinforcement length section of the reinforcement tube. For this situation, experienced sea travelers offer advice, as they don’t want to discard the reinforcement pipe. If the defective carbon steel section is repaired through proper welding before surfacing, is it necessary to inform the design institute? Also, does it need to be mentioned regarding third-party inspection? Thank you to all the wonderful sea friends. :handshake:handshake
Since the thinned portion is outside the effective reinforcement length, it is sufficient as long as the wall thickness of the thinned carbon steel section remains greater than the calculated thickness of the pipe fitting plus the additional thickness; thereafter, surfacing welding is performed and the section is processed to its original inner diameter. It’s not a big deal; there’s no need to contact the design institute. If a third-party inspector is present and sees it, then it’s up to him/her to decide.
The design institute should be informed that, although it is not within the effective reinforcement section, it is still a stressed area. The strength of the surfacing layer is generally lower than that of carbon steel. Even if you can calculate the wall thickness yourself, it still does not match the design specifications; therefore, you must inform the design institute, otherwise it may be considered fraudulent behavior.
Stack it up? Is it possible to do this? After all, the stack is different from the pipe body itself – is it reliable? Is it necessary to inform the design institute or the third-party supervisor?
This post was last edited by gn_1984 on 2018-8-3 09:20. I think the same way. Write a formal corrective action plan for the supervisor to review, explaining the situation. After all, the supervisor is watching. Forget contacting the design institute; it’s very troublesome, and they might even suggest that you discard the item outright.
This post was last edited by gn_1984 on 2018-8-3 09:27. Do you think the design institute will allow you to reuse it?
It depends on your mixing and communication skills as well as your courage: lol
Your forged pipes are made of carbon steel, while you use stainless steel. . Unlike the base material, do you think the chemical composition is not satisfactory, or are the mechanical properties not up to standard?
The forged pipe is made of carbon steel, with a stainless steel layer welded onto the inner diameter in contact with the medium. Due to defects in this welding process, the welded layer had to be removed by machining. Accidentally, 2 mm of the carbon steel base material was also removed during machining. Since it is not desired to discard the forged pipe, it is planned to weld carbon steel to that portion of the base material first, and then apply a stainless steel layer again.
I don’t think it’s necessary. . Just stack stainless steel directly; make the stack thickness greater