Can the tube sections with welding be purchased externally?
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While browsing the messages on the headquarters forum, I found a message that read: “Regarding the difference between purchasing tubular sections with welds and outsourcing their production; Question (1): Is it permissible to use tubular sections with welds purchased from outside for manufacturing pressure vessels within our own organization?” Can a supervision and inspection certificate for the tube section be issued? Question (2): If the situation in Question (1) is permitted, would it violate the requirements in C2.1.5 of TSG07-2019 \"Rules for Licensing Production and Filling Units of Special Equipment\", which explicitly states that tasks other than welding can be outsourced? Question (3): Is there any essential difference between a cylinder with welding purchased externally and a cylinder with welding manufactured by an external contractor? ” The following is the reply received from the General Administration: “Reply: Tubing sections with welds can be purchased externally, but they must undergo manufacturing supervision and inspection in accordance with the requirements of 6.1.2.1(3) of the ‘Safety Technical Supervision Regulations for Fixed Pressure Vessels’ (TSG 21-2016).” Clause C2.1.5 of the \"Rules for Licensing Production and Filling Units of Special Equipment\" (TSG 07-2019) stipulates that manufacturing units must have the capability to independently carry out all manufacturing processes such as overall assembly, welding/adhesion, pressure testing, and inspection of products; it is not allowed to outsource all the pressure-bearing components of pressure vessel products. ”
According to the General Administration’s response to this issue, tube sections with welds can be purchased externally, but they must undergo manufacturing supervision and inspection in accordance with relevant standards, and a supervision and inspection certificate must be issued. At the same time, in accordance with the provisions of C2.1.5 in TSG 07-2019, the manufacturing unit shall have the capability to independently carry out manufacturing processes such as the overall assembly of the product, welding/adhesive bonding, pressure testing, and inspection; it is not permitted to outsource the production of pressure-bearing components. Therefore, there is a fundamental difference between purchased welded cylinders and outsourced welded cylinders. -
Yes, it is allowed as per the technical specifications.
The General Administration’s response indicates that there is no legal basis for this; it is best not to outsource such tasks, as they are ambiguous. Personally, I understand it to mean that it can be outsourced or purchased from outside. Reason: 1. TSG 07-2019 and TSG 21-2016 have different focuses in terms of their scope of application; the former emphasizes qualification assessment, while the latter focuses on the manufacturing process ； 2.TSG 21-2016“(3) The following components supplied separately: heads (with welds or requiring heat treatment after forming), tube sections and shell plates with welds (adhesive joints), and heat exchange tube bundles. ”The clause is later than TSG 07-2019 C2.1.5 3. TSG 07-2019 does not explicitly state that such behavior is prohibited. Finally, try to avoid outsourcing; the two technical specifications have equal status and come into effect simultaneously, and there are misunderstandings regarding this. It is recommended that purchased components that are subject to significant compressive forces and have welds should come with inspection certificates, and that the inspections be carried out locally after they are received.
Thank you for the addition. Indeed, regarding such issues, different people may have different understandings and views. According to your analysis, although TSG 072019 and TSG 212016 are both related to the safety of special equipment, they focus on different aspects; as a result, there may be interpretative discrepancies in certain provisions. Following your advice, when purchasing welded tube sections from external suppliers, it is necessary to ensure that they come with inspection certificates, and local inspections should be carried out after the installation is complete to verify that they meet the relevant technical specifications.
This post was last edited by niat8888 on 2023-3-9 08:46. The origin of this issue lies in the fact that Shandong refuses to accept cylinder components used in products that have passed inspection and were purchased from outside the region. TSG 07 are the conditions for manufacturing permission. . It mainly relates to the requirements for evidence collection. . During evidence collection, the welding task cannot be outsourced. The product’s welded tube sections are, in essence, container components. It can be purchased from qualified suppliers, with supervision and inspection carried out in accordance with regulatory requirements. .