ASME VIII U-1(e)(1) Advice

[nde3rich]

I'm sure this has been handled before, but I could not find it in the search results but here goes:

a coupling is welded for a drain nozzle to a fin fan cooler at construction.
during a shut down,the nozzle is cut off at the nozzle side and a new 6" long piece of pipe is then welded to the existing coupling and new threaded valve installed. Is the new weld on the coupling to pipe nipple an ASME VIII weld or ASME B31.3 weld?

Any help would be greatly appreciated...

Richard S.
ASNT NDT Level III
API 510,570,653, AWS-CWI

 

[jamesl]

It is a B31.3 weld. The boundary of vessel stops at the first circumferencial weld joint of the nozzle.

 

[trottiey]

I'm a little confused by the phrase "the nozzle is cut off at the nozzle side," so let me see if I have this straight:

vessel - coupling + pipe - valve - stuff ?

Was the pipe nipple included in the manufacturer's data report, or just the coupling? As long as vessel boundary stopped at the coupling, then the weld marked '+' is a piping weld, i.e. B31.3. But your weld prep on the coupling has to meet the taper requirements of Section VIII.

 

[nde3rich]

trottiev,

vessel-weld a- threaded coupling-pipe -threaded valve original

vessel -weld a- threaded coupling now has threads ground out-new weld b- pipe-new weld c-valve.

hope this helps....



Richard S.
ASNT NDT Level III
API 510,570,653, AWS-CWI

 

[trottiey]

Ah, I get it. New weld b would be a piping weld, but by grinding out the coupling threads I think you've altered your pressure vessel. I'm guessing the manufacturer's data report claims it has a threaded nozzle there.

 

[Duwe6]

Rich, this is a "Grey" area. Since you are inside the pressure boundary of the Sect VIII Hydro, I would call it an "R"-stamp weld & a "Repair of a Routine Nature".

If the original threads remained and you were just backwelding the threaded commection, I would call it B31.3, as per jamesl's post. First weld out. NOTE: In my experience: the 'usual & customary' way to handle this backweld is to do it as an "R"-stamp weld & a "Repair of a Routine Nature". Don't understand the rational for this, but it is what folks do.


BTW, i is your buddy Roger