undertolerance 1

[xgiorg]

Hello,

Someone knows if I have to apply a undertolerance of 12,5% to calculate the minimum wall of a shell of sa-516 Gr.60? (is a steam drum, D=1300mm, nominal thickness= 30mm, 48.5kg/cm2, 270ºC, ASME I code) I suppose there exist a undertolerance to convert to the after forming value (PG-16.4).
The same question for a elliptical head.

Thanks.

 

[vesselfab]

12.5% IS PIPE FOR OVALITY IN PIPE WHERE SOME GETS THIN

HEADS ARE PURCHASED AS MINIMUM THICKNESS AND HEAD MANUFACTURER APPLIES HIS THIN OUT REQUIREMENTS

SHELLS ARE NORMALLY OK UNLESS HOT FORMED THEN YOU ADD A SMALL AMOUNT TO THICKNESS FOR THINNING DURING FORMING.

 

[xgiorg]

Thank you vesselfab. This plate is cold rolled then I don't have to add a undertolerance. Thanks

 

[kwaliteitshenk]

Vesselfab.
Sorry but 12.5% is tolerance on wallthickness for pipe and not on diameter.

 

[vesselfab]

YES SIR

I KNOW EXACTLY WHAT IT IS

pipe is not round and the id is not always correctly centered on o.d

the ovality and off center causes wall to be thin

yes sir

it is for wall thickness