Issues related to socket welding of fittings, flanges, and valves
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A new project has been initiated in the traditional chemical industry; the process package provider provided a pipeline grade table designed several years ago. With the exception of one small high-pressure oil pipeline that is welded by socket welding, all other small pipelines are welded by butt welding. SCH40 pipes of DN15~40, BE, butt weld. Flanges and valves also do not have socket welding. I reviewed the materials from several reputable design firms in the industry, and they all had more or less the same issue. During the project team’s discussion, someone suggested changing those parts that do not comply with existing standards, while leaving the rest as they are. But take butt welding of small pipes as an example: large companies have welders with high skills, so they might be able to do it well. As for the current construction subcontractors, it’s hard to determine what level of skill they possess. Also, the requirements for testing have increased. Should I go with the mainstream approach or have major surgery?
I think it’s mainly a problem on the part of the construction party. For example, you suggest socket welding for the small pipes, but when they carry out the work on site, they usually go with the method that is most convenient for them – which is quite normal
I disagree; if you propose socket welding, the drawings should be changed to reflect socket welding. Construction must be carried out in accordance with the drawings; otherwise, it will have to be redone! What does it mean to do things in the most convenient way possible? How should I phrase it if there is a leak or some problem occurs in the future?
You’re overthinking it. For some small projects, even if you suggest socket welding, the workers on site won’t follow those methods strictly; usually, they rely on their own experience when carrying out the work
Besides welding, there are many other things as well. For example, the designer specifies the number of layers and thickness of the anti-corrosion paint, but the contractor may not necessarily follow these specifications strictly; instead, they usually rely on experience when carrying out the work, and this is the case in many aspects
So, once again, it comes down to whether you pay attention to the projects you’re responsible for and whether proper monitoring is in place. If there are no requirements, and neither the owner nor the supervisor understands anything about it, then it doesn’t really matter. Anyway, according to what you say, just do the construction in the most convenient way possible. Anyway, the work in our company involves very minor details; if it’s not built according to the blueprints, it has to be demolished and rebuilt. There’s nothing to say!
Construction and design are two different things; just as with many things, there are conventions or assumptions that prevail, and many of these are not necessarily followed strictly. This is probably what is meant by theory versus practice
According to standards and specifications, pipes should not be buried underground, and the site location should not be chosen in that way. You’re overthinking it; if we go by your logic, then people wouldn’t be able to live in areas with seismic intensity of 8 or 9 degrees. It’s normal for there to be differences between what’s proposed at the construction site and what the designers suggest
The fittings, flanges, and valves have been purchased with socket weld connections; it depends on you as to how you will carry out the butt welding