Old Piping codes 1

[dahar]

Does anyone out there know where I can access a 1960 B31.1 Power Piping Code? I have a customer who is interested in raising the temperature of some existing boiler piping and I want to rerate the piping and do a stress analysis of the existing system. Since the boiler was installed in 1960 era I have been instructed to use the orignal code allowables.

 

[robsalv]

Let me clarify, I agree with the sentiment expressed by the staff engineer in that the rerate should occur to the standard of the construction day.

I agree that if you are to rerate to the current standard, then the whole suite of concurrent standards and practices need to apply.

There is a current interpretation by the NBIC on this very issue - original does NOT mean original edition and addenda.

Metengr, perhaps you should link to the interpretation and dispell any doubts.


One way to get around the rerating complexities for smaller diameter systems, is to design, flexi and construct your piping systems to the DP and DT, however conduct a cold and new hydro to the limit imposed by flange ratings (- be sure to do stress check calcs for high flange ratings). The flange rating, afterall, sets the ultimate envelope for a piping system. If you test your system to the maximum possible envelope - then any future rerates end up being a paper shuffling exercise (providing the line condition today is comparable to the hydro then) since original hydro is above or equal to the hydro required by the new DP.





Anyone like to proffer a comment regarding the hypothetical original hydro vs new pneumatic. I frankly don't have a definitive answer.

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"Life! No one get's out of it alive."
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[metengr]

Metengr, perhaps you should link to the interpretation and dispell any doubts.

Ok, here it is....

Interpretation NBI 95-19

When the NBIC references "the original code of construction" is is required to use the edition and addenda of that code used for construction?

Reply: No. The term original code of construction refers to the document itself, not the addition/addenda of the document. Repairs and alterations may be performed to the edition/addenda used for construction or to a later edition/addenda most applicable to the work.

So, as I stated above, if you intend to use an edition/addends to an earlier edition of the code you had better understand that the current eidtion of the code could contain changes to general reqyuirements, welding and fabrication that could be outdated for a re-rate!

 

[robsalv]

Thanks for putting that up Metengr. To be fair the ruling does have an each way bet as to which version of the code you should use - so it's fair to say that the staff engineer wasn't actually contradicting the ruling.




So no takers on the piping rerate question??



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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[metengr]

robsalv;
You missed my point in this. Original has no reference to edition and addendum. Yes, you can use any addition/addendum that is most applicable to the work. My point is that original does NOT force a user to go back to the original edition/addendum as some would be lead to believe by others.

 

[robsalv]

I take your point. I wasn't directly referring to whether "original" means construction code of the day or just the document itself. Your point is well made that "orignal code" means the document.

There was some discussion above about whether a rerate should be done to the construction day version of the code or current version of the code. The NBIC ruling takes an each way bet on that particular point.

Cheers

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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."