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Up Topic Welding Industry / ASME Codes / Way around QW 202.4
- - By curiousguy Date 01-28-2010 17:09
Hi all,
I have a problem with a welding process for a vessel we are fabricating. We are required to weld a 65 mm thk flange to a nozzle. The flange is ASTM A 105 and the nozzle is 304 L. But our problem is that we dont have a procedure that covers this range. and we dont have plates of 38 mm thickness either. So i was wondering if there was some way around this, like some interpretation or code case i could use that makes some clever use of the technicalities to get around this clause.
Any help will be much appreciated. Im in a bit of a tight spot here, so quick responses will be all the more welcome.
Thanks
Parent - - By spots (**) Date 01-28-2010 19:24
Is it the P-number range or the thickness range? Either way you are in a tight spot indeed.
Parent - By curiousguy Date 01-29-2010 17:44
Its a thickness range problem...
Parent - - By MBSims (****) Date 01-28-2010 23:06
Is the nozzle thickness also 65 mm?  Is it a butt weld flange or slip-on?
Parent - By curiousguy Date 01-29-2010 17:44
The flange is butt weld... and the nozzle thickness is 20 mm...
- - By curiousguy Date 01-29-2010 17:44
any ideas???
Parent - - By js55 (*****) Date 01-29-2010 18:30 Edited 01-29-2010 18:32
Are you saying the weld neck is 65mm?
So, you are welding a 65mm weld neck flange to a 20mm piece of pipe?
Unless I'm reading this wrong you are either considering the wrong part of the flange for thickness, or you C-bore the flange to fit the 20mm thickness of the pipe and you have no problem. Your qual only needs to go to 20mm.
Parent - - By curiousguy Date 01-29-2010 18:37
No im sorry the flange is slip on. The nozzle is made by rolling a 20 mm thick plate.
Parent - - By js55 (*****) Date 01-29-2010 19:02
QW-202.2(c) and QW-451.4.
Parent - - By curiousguy Date 02-01-2010 16:45
The joint is a butt joint. We have to machine a j-groove on the flange.
Parent - - By Superflux (****) Date 02-02-2010 14:27
I may be off the mark here, but does machining a bevel onto a slip on flange "transform" it into a weld-neck flange??? I didn't think ASME allowed slip-ons to be connected to vessels.
Parent - By curiousguy Date 02-02-2010 18:41
I dont think you understand what I am trying to mean here. Maybe this drawing will help clear things up.
http://img502.imageshack.us/img502/5339/53730238.jpg
I believe the welding for the flange with the nozzle shell is a butt weld. That is the joint for which I am having trouble with qualification.
Up Topic Welding Industry / ASME Codes / Way around QW 202.4

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