Let’s provide some information on the welding requirements for pipe branch connections and the qualifications required for welders
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I posted a request for help before, and I’ve encountered this issue again recently; so I’ve summarized it once more and decided to share it. I. Regarding the welding joints of branch pipes, according to GB50184-2011: and according to GB50235-2010: Requirements: 1. For butt-welded saddles, construct them in accordance with the welding branch pipe joint configuration shown in (a) above. 2. For the semi-copied lane, construct it in accordance with the plug-type welded branch fitting format shown in (b) of the above diagram. 3. For open-ended tees without reinforcement rings, either of the joint types shown in (a) and (b) in the figure above can be used. 4. For flanged tees with reinforcement rings, either the joint types (c) or (d) shown in the figure above can be used. Embedded welding branch pipe, Inserted welding branch pipe – Incorrect example! II. Regarding the scope of welding work that welders are permitted to carry out with a valid certificate, in accordance with the requirements of the \"Detailed Rules for the Assessment of Welding Operators for Special Equipment\", the following rules apply: 1. For detachable welding branch pipes, which are considered pipe plate corner joints as per the rules, the welder’s certificate must include competence in welding pipe plate corner joints. 2. In accordance with the detailed rules, for on-site butt welds, the outer diameter of the weld joint prepared by the welder must meet the minimum outer diameter requirement specified for that welder’s certification (see the table below). Examples of qualified welder certificates for tube and tube sheet welding are as follows:
Thank you for sharing the information; great work, OP
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:D:D:D Thank you for following; I’ll recommend a suitable candidate to you
I’ve learned it.* Good article, with theory and pictures
Is the welding qualification now issued by the Technical Supervision Bureau or by the Work Safety Administration? Some organizations require both certificates.
Is this correct? Placing is not placing, inserting is not inserting. It is not possible to see the thickness of the branch pipe when it is in place ； When inserted, the thickness of the main tube cannot be seen
The structural diagram is clear, but the precision of control during the actual processing process is not well managed in some units
For fixed installation, if the main pipe has no groove, the opening is made according to the inner diameter of the branch pipe; after welding, the wall thickness of the branch pipe is not visible. The wall thickness of that red branch pipe. Wrong ； For the fixed type, if the main pipe has a groove (for insertion), the opening is made according to the outer diameter of the branch pipe; after welding, the wall thickness of the main pipe cannot be seen. In the diagram, both wall thicknesses are shown clearly, which is incorrect. The diagram shows a fixed installation; the opening in the main pipe is sized based on the outer diameter of the branch pipe, and it is made quite large. This led to this result. Looking at the wall thickness, the pressure is moderate, and the welding strength is insufficient. It constitutes a serious quality defect.
This post was last edited by niat8888 on 2022-1-21 08:42; there are no obvious errors. . This D1 refers to the opening in the main pipe; it is not the outer diameter of the branch pipe, nor the inner diameter of the branch pipe! .