Risk between Welded and Seamless Vessel
Risk between Welded and Seamless Vessel
(OP)
It is know that seamless vessel will be always the best, but base on engineering calculation both is safe within the design thickness. However, base on safety point, there ma have some different. Thus, can anyone help to give me some safety factor between this two types of vessel.





RE: Risk between Welded and Seamless Vessel
No, I don't agree with your statement that a seamless vessel is always the best. Why? Improved safety - no. Improved reliability- no. Lower Cost- no.
For example using design by rules in ASME B&PV Code, welded design with good engineering practices will result in an equally safe and reliable pressure retaining item that could be manufactured at less cost. Looking at other international boiler codes I would expect the same conclusion would be arrived as I mentioned above.
Code committees are deliberate in assigning necessary strength reduction factors for use in welded fabrication. I am not going to get into detail because you should review the Code yourself to understand what is required for welded fabrication.
RE: Risk between Welded and Seamless Vessel
I am aware and have specified "seamless" pipe..(seamless only refers to an axial welded seam).......but in the case of piping beyond a certain diameter, seamless is not available.
Any explanation of terms ??
RE: Risk between Welded and Seamless Vessel
Not unusual to have high pressure, reasonably large diameter reactors with shell cans which are forgings rather than rolled plate. See the schematic near the bottom in http
jt
RE: Risk between Welded and Seamless Vessel
MJ is also right in that welded vessels can be just as safe as seamless. I hear the seamless vs. welded issue in piping and tubing all the time. A welded pipe or tube can be just as reliable and safe as seamless given it is properly fabricated and tested. The same holds true for vessels made to any recognized fabrication code.
RE: Risk between Welded and Seamless Vessel
rmw
RE: Risk between Welded and Seamless Vessel
As I mentioned before, welded vessel can be safe as seamless if following the code. Again, it can be also some reasons that make it unsafe in the long run, for example, corrossion on the weld join, since welding may spoilt the material structure. Besides, there is also possibility for the weld join (since the weakness join) to crack due to environment impact.
Thanks
Lee
RE: Risk between Welded and Seamless Vessel
cheers,
gr2vessels