UG-30(e) radial loads units

[tigny]

Hi,

in UG-30 Attachment of stiffening ring, (e) Strength of Attachment Welds,

(1) The radial pressure load from shell, [highlight #FF99FF]lb/in.[/highlight], is equal to PLs.
(2) The radial shear load is equal to [highlight]0.01[/highlight]PLsDo.

Shall I assume the factor [highlight]0.01[/highlight] is valid only for US Customary units?
Or that the mention [highlight #FF99FF]lb/in.[/highlight] is out of date?
Or both?

Yours truly,

Tigny

 

[jte]

Interesting... The 2003 addenda had SI units with a footnote, the 2004 edition lost the SI units. No mention in the summary of changes, no ASME record number or ballot that I was able to find.

I haven't really tried to derive the values, but suspect that the 0.01 term (which exists in the 2003 SI version) is not a unit conversion term but related to the 2% (odd - not 1%) mentioned in the paragraph.

jt

 

[doct9960]

tigny,

The factor 0.01 is also valid for metric or SI units.

If you look at Example L-5 in Appendix L, the following were given and calculated:
P = 15 psi
Ls = 40 in.
Do = 169 in.
Radial shear load = 0.01 (15)(40)(169) = 1014 lbs. = 4.52 kN

Converting P, Ls, & Do to SI units and calculating for the radial shear load...
P = 103.4 kPa
Ls = 1.02 m
Do = 4.29 m
Radial shear load = 0.01 (103.4)(1.02)(4.29) = 4.52 kN

The results are the same using the same factor 0.01.

 

[tigny]

Dear jte, dear doct9960,

thank you for your answers, I can step a little bit further!

Indeed in example L-5.3 , 0.01PLsDo is labelled as "lb" so 0.01 would have no units.

yours truly,

Tigny

 

[tigny]

Dear all,

sorry to bug you but I am wondering where the 0.25 coefficient in the L-5.3, allowable load for the welds come from:

It is written 2 x 0.67 x 0.25 x 7.865

2 is for weld on both sides
0.67 is for percentage of weld in intermittent weld
7.865 ksi is the allowable fillet weld stress (55% of S).

[ol]
[li]Is coef 0.25 coming from UCS-68, "Lightly loaded attachement", therefore implying paramaters pertaining to this chapter are enforced to this particular calculation?
[/li]
[li]May I then use a factor 1 for UHA, high alloy steel construction?[/li]
[/ol]

yours truly,

tigny

 

[bernoullies123]

0.25 = 1/4" min. fillet weld leg size

 

[tigny]

Oops, thank you bernoullies123.

I was looking all over the code for this value...

I was stuck with the metric value (6mm) but should have looked more thouroughly in the last two paragraphs of L-5.3 where 1/4" appears twice.

Thanks again,

Tigny