using pipe for vessel shell
using pipe for vessel shell
(OP)
just ran calcs for vessel shell thickness which 36" OD sch. 40 pipe can be used. question is what sizes are seamless pipes manufactured to? also if out of range what sizes are erw pipes manufactured to? or will this have to be fabricated as a can of itself?





RE: using pipe for vessel shell
ERW pipe can be manufacutred to whatever WT you require as well & is usually more cost effective, if the code allows its use for your application.
The grade of material will affect the process of manufacture and availability of the material.
RE: using pipe for vessel shell
Welded pipe is available as ERW but I prefer to specify double submerged arc welded pipe (DSAW as opposed to ERW) pipe for these large sizes as I believe the overall quality will be better.
DSAW pipe is often ordered as ASTM A671 material (though some people order A672 which is very similar). The grade will correspond to the grade of plate used for manufacture of the pipe. Grade CC60 would be A516-60 plate and Grade CC70 would be A516-70 plate. Different classes are available and I typically specify Class 22 which includes PWHT and 100% RT. Class 32 would be normalized.
You would have to check the rules of the vessel design code that applied to this project to see whether or not it would accept the use of welded pipe (either ERW or SAW) as the starting material for a vessel shell.
RE: using pipe for vessel shell
So, if a large bore "pipe" can be bought that meets the material spec for PV's at a lower cost than seammless "pipe" forced into that larger a diameter, you save construction time for the vessel walls.
RE: using pipe for vessel shell
David
RE: using pipe for vessel shell
RE: using pipe for vessel shell
The original poster (sksmechanical) said that he (or she) is making a Vessel, right?
Now if this was to be a Vessel 10 feet in diameter it would be made of rolled "Plate" with welded seams or joints.
So,
What is the problem with using a rolled and "Welded Plate Cylinder" 36" in diameter?
As long as the correct weld method is used, I see no problem.
RE: using pipe for vessel shell
I suspect that for DSAW the answer is yes (thought for EFW I'm not so sure) but I haven't confirmed this and a check would need to be done before proceeding with this option.
Since the pipe will be made following the procedures outlined in the ASTM standard, you likely have little ability to influence the weld method. Having said all this, there is the issue that for use in an ASME vessel, you would need to assure that the starting material meet an SA (ASME) Standard as opposed to an A (ASTM) standard. For example, ASME SA671 as opposed to ASTM A671.
RE: using pipe for vessel shell
Regards,
Mike
RE: using pipe for vessel shell
RE: using pipe for vessel shell
RE: using pipe for vessel shell
RE: using pipe for vessel shell
I don't question whether I can use a weld fitting, I just include it in the test. I don't question whether I can use a valve or a flange, I just include them in the test. Same with pipe manufactured to a standard like API 5L. The boiler code speaks to using stuff that was built to a standard and says it is OK.
I would use ERW for this project, count the money I saved, and never look back.
David
RE: using pipe for vessel shell
RE: using pipe for vessel shell
RE: using pipe for vessel shell
GBC