Elbow with extra bevel
Elbow with extra bevel
(OP)
Good evening.
I have a doubt about an elbow that I received. It's a 90deg elbow 10 inch sch 120. It came with an extra bevel of the exterior part of the short radius like in the photo attached. It is normal to be like that?
Thank you!
I have a doubt about an elbow that I received. It's a 90deg elbow 10 inch sch 120. It came with an extra bevel of the exterior part of the short radius like in the photo attached. It is normal to be like that?
Thank you!





RE: Elbow with extra bevel
Assume the ID of the elbow is a perfect circle of diameter = ??? (Verify this, by the way).
What is the thickness of the wall at the upper tangent, introdos, lower tangent, extrados?
Is the beveled surface truly flat, or does it wave back and forth?
If the beveled surface is flat, does the other beveled surface lay 90 degrees to the first?
At the second surface, what are the same four thicknesses?
RE: Elbow with extra bevel
RE: Elbow with extra bevel
Piping Design Central
RE: Elbow with extra bevel
Looks like a fairly thick elbow so you can probably dress it up a bit or reject it.
Have a look at table 12 of ASME B 16.9 and then work out if it passes or not. Personally I don't think it is and it should be rejected.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Elbow with extra bevel
RE: Elbow with extra bevel
RE: Elbow with extra bevel
In most piping systems there are components such as valves, castings, heavier header sections, and equipment nozzles which are welded to the pipe.
In such instances the heavier sections are machined to match the lighter pipe wall and the excess thickness tapered both internally and externally to form a transition zone.
Limits imposed by the various codes for this transition zone are fairly uniform.
The external surface of the heavier component is tapered at an angle of 30° maximum for a minimum length equal to 1.1/2 times the pipe minimum wall thickness and then at 45° for a minimum of 1.1/2 times the pipe minimum wall.
Internally, either a straight bore followed by a 30° slope or a taper bore at a maximum slope of 1 to 4 for a minimum distance of 2 times the pipe minimum wall are required.
The surface of the weld can also be tapered to accommodate differing thickness. This taper should not exceed 30°. It may be necessary to deposit weld metal to assure that these limits are not violated.
Below some tables with acceptable design for unequal wall thicknesses acc to ASME B31.8
http://www.wermac.org/documents/unequal_wallthickn...
RE: Elbow with extra bevel
And it may be an optical illusion, but the "secondary bevel" sort of looks like it's uneven around the circumference, which would be really odd.
* added word, 'not*
RE: Elbow with extra bevel
RE: Elbow with extra bevel
That is exactly right.
This elbow appears to have been hot formed, the result of which is a thicker wall thickness at the intrados and a thinner wall at the extrados.
RE: Elbow with extra bevel
Best regards.
RE: Elbow with extra bevel
RE: Elbow with extra bevel
All we know is the elbow is 10" sch 120.
Design code?
material?
Mating element
Wall thickness / schedule?
material?
My suspicion is you're welding a sch 120 elbow to something thinner or the vendor has given you an elbow thicker than sch 120 in the body so has machined off the "excess" or you actually need something thinner.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Elbow with extra bevel
RE: Elbow with extra bevel
The main reason manufacturers go with the OD transition rather than the ID transition is when they want the thru bore of the fitting to be as close to the I.D. (piggability issues).
This is perfectly normal unless you're Kinder Morgan.
RE: Elbow with extra bevel
RE: Elbow with extra bevel