Welding Coupling to Pipe Neck according to Figure UW-16.2 (L) 2

[Alejandro Cano]

Hello,

I have the a Full Coupling 2.5" #3000 threaded, welded into a 4" NPS SCH. XXS Elbow right in the neck.

Please see the attached sketch.

This is an ASME U vessel, is this legal according to ASME VIII DIV. 1? I want to apply the configuration of Figure UW-16.2 (L), but I don't know what size of fillet weld use (there is space to use 3/8" fillet).

Hope you can help me.

Alejandro Cano.

 

[david339933]

Looks like it is inside the shell? If so, it is not a Code weld.

 

[SnTMan]

There must be a better detail, but...

I agree w/ david339933, not on the pressure booundary, do whatever you like.

Regards,

Mike

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

 

[Alejandro Cano]

david339933 / SnTMan, thank you for your quick response.

Just for my understanding, yes, the coupling is an internal, but it is welded to a process nozzle with inside projection. Then, since the coupling and elbow are under internal pressure and the same external pressure, it goes outside the pressure boundary?

Regards,

Alejandro.

 

[david339933]

Consider what will happen if there is a catastrophic failure of the fillet weld on the cplg...not much...a cplg inside the vessel.

Standard Designation: BPV Section VIII Div 1
Edition/Addenda:
Para./Fig./Table No:
Subject Description: Section VIII, Division 1 (1998 Edition, 1999 Addenda); U-1(e)(1)(a)
Date Issued: 11/06/2000
Record Number: BC00-596
Interpretation Number : VIII-1-01-09
Question(s) and Reply(ies):

Question: An inlet nozzle extends into the shell of a pressure vessel and makes a welded connection (tack weld) to an internal pipe fitting (malleable cast iron elbow). May this internal weld be considered outside the scope of the Code under U-1(e)(1)(a) of Section VIII, Division l?

Reply: Yes.