UCS79(d)(2)(-d) forming head thickness reduction.

[mechengineer]

Hi,
As per UCS79(d)(2)(-d), is it acceptable if the thickness reduction more than 10% and calculated elongation less than 5% for the dished head of nom. thk=9.53 mm (after forming min. thk.=6.5 mm). The reduction is ~32%, is it allowed?
In another word, how to control the thickness reduction of the dished head and the forming head quality by ASME code except it shall be larger than the required thickness. There is a limit (10~16% recommended) for the reduction of forming head in China's code GB/T25198.
Regards

 

[r6155]

What is the design required thickness?

Regards

 

[mechengineer]

@r6155,
The question should be " how to control the thickness reduction of the dished head and the forming head quality by ASME code except it shall be larger than the required thickness".
Regards

 

[GD2]

UCS 79 should be clear on this. I don't have the latest copy but I guess there will be exceptions for P1 Group 1 and 2 materials. Can you cut and paste the UCS 79 para?

GDD
Canada

 

[mechengineer]

My opinion is that UCS 79 should provide the limit of thickness reduction for cold forming head, like China's code GB/T25198. Another example is that the negotive tolerance (12.5%) of pipe is given by B31.3.