Reinforcing Pad vs Gussets 4

[Packermanfan]

Hi all, the COMPRESS software we use for validating ASME Code designs does not support gussets. This becomes a problem with higher temperatures and pressures, as the nozzles are usually the limiting factor. Forming metal into a "dome" to fit the ends of elliptical heads to use as repad is much harder than adding gussets welded to the head and nozzle.

My question is, how does one validate a design when gussets need to be used to reinforce inlet/outlet nozzles? Thickness of material and repad equations are laid out in the code book, but there is almost no mention of gussets.

 

[jt1234]

EngineerEPC,
Good question you are asking me since I dealt with many tangential or hill sided nozzles, some are very big. It can be either in circumferential direction or longitudinal direction.
From Fig 37.1, the key is the sized of the opening. Pick tangential(circumferential) nozzle for example, assume the oblong opening is 24" in tangential direction and 16" in longitudinal direction.
To reinforced the 24" opening side, F can be 0.5 if use integrally nozzle. F shall be 1 if you use re-pad (this is what I disagree with Code. This is the angle 90 and F can be 05, regardless re-pad or integrally reinforced due to the stress on these area is PR/2t, longitudinal stress, but please still use 1 per code). For the 16" opening in longitudinal direction, F will be 1 as it is Angle 0.
The maximum pad size can be an oblong shape 48" x 32". (twice of the opening)
Reasoning the same for opening in longitudinal direction.
You will need to make 2 runs if commercial software can not perform oblong opening or hill sided nozzles, to find out the width of repaid in Angle 0 and 90, and smoothly taper to an oblong re-pad or use integral reinforcement, or use a thick insert plate to make fabrication easy. See attached sketch.
All kinds of people in this post talking about things some of them are odd to me, either not industrial common practice or not common sense. Be careful to pick up their opinion. Any design question, please post and if I know the answer and have time, I will reply.

 

[EngineerEPC]

Dear Sir, Thank you for taking the time to provide a detailed reply and a sketch.
Really grateful.

Thanks and regards
EngineerEPC

 

[r6155]

@ jt1234
1) Not always the insert plate is considered an integral connection, it depends on the welding of the nozzle to it.
2) The dimension of the insert plate should be as simple as possible, circular shape is best (not rectangular as in the sketch).
3) What is the NDE of the weld the insert plate to the shell?

Regards

 

[jt1234]

r6155, you probably has not done many as I have done in the past 30 years for so many big oil companies around the world, US, south America, China, Russian, Singapore, Mexico, Middle East, etc. I don't think I need to reply to you.

 

[r6155]

@ jt1234
Me too, for the past 54 years, including oil and gas, NUCLEAR, food, etc., as a design engineer and also inspection.
No offense.

Regards

 

[RadiateurFou]

@jt1234 It is not the first time i see you putting ego in your answer. Please don't think to much about questions and answer them to your best, as it is always valuable ressources for us new engineers.