Reinforcement opening or reinforcement brach

[Kenyi]

Hi everybody!
I have a case where I do not know how treat it, a reinforcement branch in piping or a reinforcement nozzle in pressure vessel?

It has a Head of 60" where go in 6 pipes (36",26",12",26", 12" and 26") and go out two pipes of 36", this head is 10 mts long.

If I use ASME 31.3, is not aplicable the calculation method accordance to: Dh/Th >= 100 and Db < Dh/2 from 304.3.1 (b)(2). But If I use ASME VIII Div 1, is not applicable neither because in UG-36 (b) nozzle diameter Dv/2 or less then 20"

Where can I find a guide to know which code I have to use?

 

[CodeRef]

Kenyi,
Are you using the 07 Edition of VIII-1? If so, look for the following words in UG-36(b)(1) of the 07 Edition of VIII-1 and then go to Appendix 1-10. The 07 Edition has incorporated Code Case 2398 into the 07 Edition of VIII-1
"..............Alternatively, openings in cylindrical or conical shells exceeding these limits may be designed for internal pressure using the rules of 1-10 in lieu of those given in 1-7(a) and/or 1-7(b)................"

Also, consult with your Authorized Inspector.

There are three kinds of people in this world; those who can Google and those who can't.

 

[CodeRef]

I missed adding this to my last post:

Because you are placing openings in a head and not radial openings in a shell, you have to apply the rules given in UG-36(b)(2) which requires using a conical section meeting the rules of UG-36(e).
Good Luck!

There are three kinds of people in this world; those who can Google and those who can't.

 

[stanm]

This "head" sounds more like a header as it's 10m long.

Kenyi, you seem to be looking for a suitable application standard. It would help us to understand more if you could describe the equipment that you are designing and its purpose/application. Is this a pipework system or perhaps a boiler component? Please post more information.

 

[Kenyi]

Hi CodeJackal,
Thank you for your comments, I found the rules 1-10 I will review it.

stanm, sorry about my explaination you are rigth it is a header (run Pipe) or in term of Section VIII it is a shell (vessel) I think is more a vessel than a header. I am not designing from the beginning, I am modifying a work that was uncomplete by others. Its purpose is collect bifasic fluid (gas and liquid mix)from several stations, after that send this fluid to separator...and so on.

Regards

 

[stanm]

Kenyi,

If the purpose is fluid collection and onward transmission it sounds more like a piping application. If the design limitations in ASME B31.3 304.3.1 are exceeded then the alternatives in 304.7.2 (additional stress analysis/proof testing) would be painful so I would agree with CodeJackal that ASME VIII-1 Appendix 1 would be a better source. The only other point to watch is if you have to consider additional loads other than pressure. If there are shear/bending loads at the nozzle/shell (branch/header) connections then the rules you follow will have to be applicable to the size of connections you have.

 

[Kenyi]

CodeJackal,
I reviewed 1-10 but said:
"(d) Caution to the Designer. Appendix 1-7(b) design
methods are particularly applicable to large bolted flanged
nozzles in relatively thin (Di /t > 100) vessels when the
vessel nozzle flange is located close to the nozzle/shell
intersection."
So, I have to apply 1-7, but I`m a little confuse, because 1-7 (b) is for radial nozzles, so I have to apply 1-7(a). If I am right, I only have to provided with reinforcement as said in 1-7 (a)(1) and 1-7(a)(2).

stanm,
That is exactly what I did, I just wanted to know if I was right.

It is attached a power point file with an esquematic about headers that I am modifying.

Thanks for your comments!

 

[CodeRef]

esquematic= schematic. That gave me a laugh!!

It is your decision to use VIII-1 because in your opinion, it provides rules that address this particular design more closely than others you are familiar with.

With that said, from the PPT, it appears that you have a 60" diameter header, 10 meters long, with six inlet openings and two outlet openings, none of which are in the end heads as you stated when prompted by stanm. (thanks stanm!)

It also appears from the PPT, that the two 36” outlets are radial to the header. I cannot tell if the six inlets are radial to the header, there could be elbows welded to the inlets just prior to going into the header? If these are radial nozzles, use 1-7 (b) along with UG-36 or use 1-10.

You can use 1-7(a) if the nozzles are not radial openings and are more tangential (off to the side such as a hillside nozzle).

Keep this in mind though, if you use use the longest dimension of an oval type opening (such as would be for a nonradial type opening) and calculate as a radial opening, by utlizing the most conservative dimension, you should be safe.
After all, isn't an nozzle that is greater than ½ the vessel diameter still be considered radial? regardless of where it is centered?

 

[stanm]

Kenyi,

Some of the openings on the header look to be quite close to each other. You may also need to check mutiple openings for interaction. Does this system operate at elevated temperature? If yes then the expansion stresses may be a controlling condition.

 

[Kenyi]

stanm,
I already separate every pipe to each other. Temperature is not elevated (Design temp=150ºC)

CodeJackal,
sorry about "esquematic" some times I think in spanish.