Fitting welding
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We encountered such a problem during our production process: after connecting a tee to the pipeline, it was necessary to weld a elbow right after it, that is, the tee and the elbow were to be welded directly together. Many welders said that this couldn’t be done, but they couldn’t provide any evidence for their claim. I also searched for lots of information, but found no rules stating that this was not allowed. The diameter of the pipeline is DN25, and the pressure is PN=4.0MPa. Please give me more guidance
Are the fittings you mentioned all of the socket-weld type? That would be a bit difficult, because generally DN25 fittings are socket-type; how can two socket types be welded together? This post was last edited by flying1357 on 2008-1-30 17:34.]
It can be welded directly; neither the specifications nor the design manual prohibit doing so. Not all fittings with a nominal diameter of less than 40 are welded by socket welding; the small-diameter fittings I have encountered, those with a nominal diameter under 40, are generally welded by butt welding. Pipe fittings formed by pressing like this should be able to be welded directly, whether in terms of weld strength and the weld heat-affected zone or the distance requirements between circumferential welds as specified in the standards.
If it’s welded, it’s definitely possible
The design manual doesn’t prohibit doing this either. Ah, just do the calculations – as long as the strength is sufficient, it’s okay
We encountered such a problem during our production process: after connecting a tee to the pipeline, it was necessary to weld a elbow right after it, that is, the tee and the elbow were to be welded directly together. Many welders said that this couldn’t be done, but they couldn’t provide any evidence for their claim. I also searched for lots of information, but found no rules stating that this was not allowed. The diameter of the pipeline is DN25, and the pressure is PN=4.0MPa. I would appreciate your guidance. It should be noted that all the pipe fittings mentioned above are buttwelded pipe fittings, with diameters all within DN65”
Generally, for DN25 fittings, socket welding is the preferred method; moreover, with a pressure of 40 BAR, it is better to carry out butt welding after adding a 50 MM splice.
Since your fittings are all socket-welded, they cannot be welded directly. If they are butt-welded, then it’s possible to weld them
There can be no problems with butt-welded pipe fittings.
I have the same problem; thanks to my kind friend for the answer!