Can U-tube joints be made when the joining conditions do not meet standard requirements?
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The workers bent the U-shaped tube incorrectly; the tube with the largest radius was lost, and there are two shorter tubes left that they want to join together for use. They asked me if that was possible, as the standards allow joining tubes when the length of the straight sections is greater than 6000 mm. Since our straight sections are shorter than that amount, I refused to allow them to join the tubes together. The next day, the workshop supervisor asked me for the assembly drawings. I asked who had given permission, and he said it was a certain vice president who is in charge of equipment, procurement, and logistics; he holds a high position in the company, ranking second only to the boss. During the meal, everyone was sitting together. The deputy manager said that it was difficult to find one or two of those tubes, so it would be better to combine them instead. I didn’t say anything. The workshop supervisor then asked me if I agreed to do it; I said that technically I wasn’t in favor, but it was the manager who decided. What’s bothering me now is that I don’t want to produce any written documents or drawings, but if the workshop insists on it from me, can I still do it? Could there be any problems? Any drawings I create are based on standards, and I don’t want to deviate from them for fear of not being able to take responsibility. Am I overthinking it?
Who agrees should be the one to sign; are you still planning to sign something that violates the standards?
Principles must be upheld: no diagrams may be produced, no conclusions may be written, and absolutely no signatures may be given.
Principles must be upheld; no modifications should be made. If the supervisor gives orders, it’s best not to sign on the drawings oneself, but to let the supervisor do so
I’m using the original poster’s post to ask: although the standard allows for joining sections when the straight sections are longer than 6 meters, in the case of a U-shaped tube, where the straight sections are 4 meters long each, and one heat exchange tube consists of two such straight sections plus a bend, resulting in a total length that exceeds the usual 6-meter supply length for steel tubes, what should be done if joining isn’t possible?
It’s possible to allow stitching, but it’s also okay not to stitch; in such cases, it’s generally better to use the whole piece without stitching
In this case, the entire pipe isn’t long enough; generally, steel pipes are available in lengths of 6 meters, right?
Low pressure is fine; it can be handled in accordance with the standard splicing requirements, but it’s important to discuss this with the inspection team first.
Dude, who told you that the length of the pipe has to be 6 meters? Look, there are standards for 9-meter and 12-meter lengths as well. Currently, abroad, cold-drawn heat exchange tubes that are over 200 meters long can be manufactured. Also, in principle, heat exchanger tubes cannot be joined together. In particular, high-pressure ones are clearly not allowed to be combined. If the landlord insists on sticking to principles and taking responsibility, problems will arise.
It’s just passing the buck anyway; whoever agrees signs. He’s a leader; you can’t be forceful with him, but you can try a gentle approach. If splicing is required, then carry out pressure tests at 2 times or even 2.5 times the normal level, as well as ball passing tests, non-destructive testing, and all the other relevant procedures
The pipes were still joined together, but I didn’t provide any drawings or sign off on it; I’ll just pretend I don’t know about it. It’s not my responsibility to deal with this matter. Still, I believe that in units involved in the manufacturing of special equipment, administrative orders should give way to technical considerations – only products made in accordance with standards and specifications can ensure quality, which is also a form of self-protection.