Exchanger tubes AW tolerance for ASME VIII-1 Calculation 2

[FPPE]

Hi,

Should we consider a 10% tolerance on wall thickness for calculation of exchanger tubes (AW) according to ASME VIII-1?
I didn't find any requirement in the code about this.

Thanks in advance

 

[r6155]

Interpretation Detail
Standard Designation: BPV Section VIII Div 1
Edition/Addenda: 2017 edition
Para./Fig./Table No: UG-16(d)
Subject Description: Pipe Undertolerance
Date Issued: 11/04/2019
Record Number: 19-1218
Interpretation Number : BPV VIII-1-19-18
Question(s) and Reply(ies): Background Information: Section VIII Div. 1 paragraph UG￾
16(d) requires that the manufacturing undertolerance on wall
thickness to be taken into account when pipe is ordered by its
nominal wall thickness. These questions pertain to pipe
ordered to a minimum wall thickness that includes the
corrosion allowance.
Question(1): If permitted by the applicable pipe specification
(e.g., SA-335 and SA-999), does the Code allow pipe to be
ordered to a minimum wall thickness?
Reply(1): Yes
Question(2): If the answer to Question(1) is Yes, is the pipe
manufacturing undertolerance in UG-16(d) mandatory for
such pipe?
Reply(2): No.
Question(3): If the answer to Question(1) is Yes, shall the
minimum thickness be indicated on the Manufacturer's Data
Report?
Reply(3): Yes

Regards

 

[Christine74]

r6155, this thread is about ordering Tubing based on Average Wall thickness, but that interpretation is about ordering Pipe based on Minimum Wall thickness.

FPPE, "This is why I ask my question again, when ordering tubes in SA179 or SA210 AW, we are theoretically ordering a product that does not comply with ASME, right?"

This is a trickier question. I'm not sure but my guess is that if you ordered, say, SA-179 tubes that were 11 BWG AW (0.120 inches) thick, the mill would actually supply 12 BWG MW (0.109 inches) tubes that were dual-certified as also meeting 11 BWG AW. So possibly still in compliance with Code. Just my guess though.


-Christine

 

[FPPE]

Thank you Christine, in truth we have already noticed this, probably in the material certificates they solve this way.