Korbogen head in ASME VIII

[ronfrend]

Can anyone advise if a Korbogen Head (DIN 28013) is acceptable as an elliptical head as per ASME VIII div 1? I have a vendor who insists it is but when I look at the dimensions it does not seem to comply with ASME VIII.
Thanks in advance

Ron Frend

http://www.predicon.net

 

[Shmulik]

Ron Frend: in my opinion, it is not.
The shape of semiellipsoidal form is well defined at UG-32(d) with its acceptable approximation: "An acceptable approximation of a 2:1 ellipsoidal head is one with a knuckle radius of 0.17D and a spherical radius of 0.90D".

"Korbogen" shape based on knuckle radius of 0.154D and spherical radius of 0.80D which exceed UG-81(a) acceptable tolerances for formed heads.

 

[marty007]

Ron Frend,

I don't know how your AI would approach this question, but I ran a very very simple FEA just out of curiosity and the Korbogen Head actually produces lower stresses than the standard ASME S.E. head. It also is very close to the requirement of UG-32(d) where half the minor axis equals one-fourth of the inside diameter of the head skirt.

If all else fails, you could calculate the head as a flanged/dished head and enter the real radii.

Sorry that I'm not giving a yes/no... ask your AI.

Cheers,
Marty

 

[AMinati]

Assume your Korbogen Head is elliptical (or according ASME Code) and check the tollerances of the real shape against the theoretical. If the check pass the head can be accepted as elliptical (or according ASME Code) See also UG-81.

Best Regards

AMinati

 

[Fizza453]

Korbogen Head (DIN 28013) heads do not meet UG-81 tollerances against 2:1 ASME heads (KR: 0.17D and CR:0.9D).
I would agree with Marty007, treat this head as F&D and check if it is meeting design requirements of ASME.

Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN