Re: Branch outlets using threadolets

From: <Gordon.Reddek@Alcan.com>
Date: Wed Jan 28 2004 - 17:55:00 EST

Jim,

ASME B31.3 paragraph 304.3.3 (e) multiple branches is about the closest clause that applies. In the case of a threadolet, the threadolet has the reinforcing built in so you do not have to worry about reinforcing the hole. It appears that a spacing of 1.5 times the diameter of the opening is OK. You did not state the size of the threadolet but it is generally not greater than one size less than half of the pipe diameter. Needless to say, make sure the threadolet rating exceeds that of the MAOP of the line.
That -50C is a worry. Make sure you satisfy all the code requirements for service at that low temperature. Steel becomes brittle at those sorts of temperatures and you must concern yourself with allowable stresses, heat treatment of the welds, NDT etc. I have not had to worry about that for some time so I do not have my finger on the pulse of those requirements. Check the code carefully for "low temperature requirements" The 5" pipe is a hoot. I know they list it in catalogues but it is seldom seen in real life.

Hope that helps.

Gordon

"jdozorec" <jim.dozorec@natoil.com>
29/01/2004 06:01 AM
Please respond to PipingDesign

         To:     PipingDesign@yahoogroups.com
         cc:
         Subject:        [PipingDesign] Branch outlets using threadolets

Hello,

I need some guidance regarding a oilfield piping design where I looking at using 2 threadolets on a 5" 5000 psi working pressure piping run with the first threadolet at 5 3/8" from the end of the pipe which is welded to a mud gate valve end connection and the second threadolet at 12" away from the first threadolet and on the same side as the first. The piping components are all for H2S service and will be used in an environment where the temperature will range from -50 deg. C to +40 deg. C. The ASME B31.3 code is somewhat unclear on whether this type of configuration is allowed. It does say that threadolets (as per Table K326.1) are OK but not exactly whether having them side by side is OK.

Can someone address this topic, please?

Jim

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[Non-text portions of this message have been removed] Received on Wed Jan 28 17:55:00 2004