Body flanges frontal face planitude tolerance

[PeterWay]

Hi to all,
I'd like to rise a couple of questions, concerning heat exchangers body flanges, for water/vapor services:
which is the body flange frontal face planitude tolerance?
Is there any requirement in Asme viii div1 or in another design code?
To add more data, discussion comes between purchaser / workshop / designers, since some deviations in body flanges planitude are observed but could be corrected with gaskets i.e. PTFE Goretex. Even if the solution is usual, still there is a construction defect. So, which could be a reasonable and realistic requirement:
- Ignore defects while they are in the range of being corrected by the gaskets.
- Take some general mechanical requirements tolerance and stay strict on that point.
- Other...
Thanks a lot in advance.

 

[SnTMan]

PeterWay, TEMA R-6.33 requires flatness of "1/32 in maximum deviation from any reference plane", tThis "shall not occur in less than a 20 deg. arc." For Class B & C exchangers flatness only need be such as to pass the hydro. I believe some client specs have requirements similar to Class R exchangers.

These kinds of tolerances are not generally burdensome to meet and have been shown to meet the need. There may be some class of work where closer tolerance are needed.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[BJI]

Gaskets don't 'correct' defects, defects only decrease the gasket's ability to seal effectively (or at all). I would not accept anything outside of tolerance for new construction, re-machine as required. As well as the TEMA reference, you can also refer to ASME PCC-1 Appendix D for guidance.

 

[PeterWay]

Thanks a lot StNMan and BJI! Very useful comments.

 

[PeterWay]

SntMan / BJI,
Another question, in the new version of TEMA the Clause R-6.33 does not exist, neither the hidrotest requirement for class B & C exchanger flange flatness. It on the 9th edition, but not in the 10th, am I right or it has been stated in another part of the Standard?
Thanks in advance!

 

[SnTMan]

PeterWay, I don't have the 10th, can't say. Sorry.

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[PeterWay]

Ok thanks SnTMan, attached I'm sending the page, I'm asking just in case because I've searched and not found it. Attached the page.[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1594389403/tips/TEMA-10th-Edition-2019-pdf_apqtlh.pdf[/url]
Against the previous
[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1594389491/tips/TEMA_Standard_1999_alwsep.pdf[/url]
Well, I'll keep searching. In any case, appendix D & E from PCC-1 are a good reference!

 

[SnTMan]

PeterWay, TEMA tends to address subjects not found in the Code, or in some cases information not found elsewhere. I have seen the Standards, over the years, drop various subjects where the information was available in other sources. I'd guess that the PCC-1 info obviates the need in TEMA.

In the 9th Index, "Gasket Surfaces" is the first sub-head under "Tolerances". I'd guess the entry is deleted in the 10th.

BTW, I was not familiar with the word "planitude". Thx for the new one



The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[PeterWay]

Yeah, well should have said flatness , thnx to you!