Publication for ASME Code Corrections? 2

[klonteig]

Can someone tell me if and where corrections for AMSE codes are made available?

Specifically - In B31.3 the formula for wall thickness of a pipe under internal pressure (Sect. 304.1.2) has two formulas. One of the includes a weld strength reduction factor (W), and the other does not. A workbook I received from attending a course on B31.3 uses these formuals, but the formulas it uses both have the W factor in them. It even goes so far as to explain that the W is a new addition to the 2004 edition of the code, etc. I am wondering if this was something that was missed when the code was published (seems strange)?!?!

Thanks.

 

[FIF99]

Hi,
As far as I can see no error occur. The section for w.t. calculation shows two formula's, one based on the OD of the pipe and the other based on the ID of the pipe as parameter in the formula.
Both formula's (3a and 3b) include the weld joint factor Ej listed in table 302.3.4
Which edition are you looking at?
We, within our application, base our wall calculations on formula 3a, i.e. based on piping with a nominal OD.

Regards.

 

[ijzer]

In the new edition of B31.3 (2004) there are now two "weld factors"
One is the original weld quality factor (e.g 0.85 or 1) depending on the extent of NDT on the long weld.
The second one is new and is a weld stress reduction factor for long welds operating in the creep region (1 to 0.5).
I agree with klonteig that this factor shall also be used in formula 3a.

 

[FIF99]

Hi,

OK, I was looking in the old (2002) edition. Thanks!

I assume that the use of the additional W factor (creep) is explained further in the 2004 edition. Most probably the use of it is related to the maximum design temperature?

Within the old 2002 edition is stipulated how to assess design stresses in section 302.3.2 part d, if creep is expected to occur.
I don't have the 2004 edition available on this moment, but will look at it.
Thanks for the info.

Regards.

 

[richay]

The "errata" for the code can be obtained from this link:

http://cstools.asme.org/csconnect/pdf/CommitteeFiles/15462.PDF.

Equation 3a (as originally published) is wrong, it should include the new W term.

Richard Ay
COADE, Inc.

 

[klonteig]

Thanks a lot everyone.

All my questions were answered perfectly!

I'm new to the site, but can already appreciate the amazing potential it has.

Thanks again.