Is there a connection like UW-13 for direct connection of Body flange to spherical heads? 3

[goutam_freelance]

Referring to Fig MA1 Fig1.6, the weld type indicated by OP may not be covered by code.

Also, Type C( bolted dished end ) connection needs to meet additional requirements of weld due to bolt forces and moments, refer MA1, Cl. 1.6.

 

[r6155]

@ goutam
You are very confused.
I'm sorry to tell you, but I suggest you take some pressure vessel training.

Regards

 

[goutam_freelance]

@r6165

I do not agree. However you can disagree as you have the right to do so even though there may be some impediment here.

I stop this here as nothing will come out of this from me more than what has already been said. Anyone can leave it or take it.

 

[jt1234]

Wrong r6155

 

[r6155]

@ jt1234

Again, you are not helping the OP.
Do you have any experience with the OP issue?

 

[Cobra17]

Why does UW-3(c) reference connecting flanges to formed heads, and per UG-32, hemispherical heads are considered formed.

UW-3(a) says any welded joint within a formed head is Cat A, and specifically states circ joints to the main shell, transitions in diameters , nozzles or communicating chambers.

Where UW-3(c) says flanges to flat heads, formed heads, transitions in diameter, nozzles or communicating chambers? did they leave out flanges in UW-3(a)? probably not because its covered by UW-3(c).

(a) Category A. Longitudinal and spiral welded joints
within the main shell, communicating chambers, transitions
in diameter, or nozzles; any welded joint within a
sphere, within a formed or flat head, or within the side
plates of a flat‐sided vessel; any butt-welded joint within
a flat tubesheet; circumferential welded joints connecting
hemispherical heads to main shells, to transitions in
diameters, to nozzles, or to communicating chambers

(c) Category C. Welded joints connecting flanges, lap
joint stub ends, tubesheets, diffusion welded plate packs,
or flat heads to main shell, to formed heads, to transitions
in diameter, to nozzles, or to communicating chambers
any welded joint connecting one side plate to another
side plate of a flat‐sided vessel.


UG-32 FORMED HEADS, AND SECTIONS,
PRESSURE ON CONCAVE SIDE
(a) The minimum required thickness at the thinnest
point after forming of ellipsoidal, torispherical, hemispherical,
conical, and toriconical heads under pressure
on the concave side (plus heads) shall be computed by
the appropriate formulas in this paragraph

 

[r6155]

@ Cobra17
a) You are one of those who gets confused with a hemispherical head
b) Have you ever seen how a hemispherical head is made with a diameter of 500 mm or 3000 mm, for example?
c) Did you see my post Nov 15?

Regards

 

[Cobra17]

@r6155

do you have any code references or interpretations that specifically state that a hemi head to a flange is a Cat. A weld?

"see UW", "Read again UW", "Why don't you read the text and not the sketch", "See also figure UW-3 on the left, the spherical head", "see my sketch" does no good in helping people see your points.

If you look back at my post, I gave code specific sections for people to read.

 

[r6155]

@ Cobra17
My drawing from the post Nov 15 is sufficient.
I'm sorry you don't understand.
I can't do more for you if you don't put a minimum effort into reading the codes in all their sections.

Regards

 

[Cobra17]

@r6155
Please help me understand.

by the picture you posted, a flange to hemi head is a Cat A.

Using Figure UW-3
- A hemi head to a shell circ. is Cat A
- A shell section to a shell section is Cat B.
- A nozzle pipe to another nozzle pipe (nozzle shown on the top side of the vessel) is also a Cat B. Also shown this way on the F&D head nozzle on the right.
- A nozzle pipe to a weld neck flange is Cat C (same nozzle as above), and a nozzle pipe to slip-on flange is Cat C (F&D head nozzle on the right)

by my understanding, flange attachments are Cat C, and from my previous post, UW-3(c) supports that.

(c) Category C. Welded joints connecting flanges, lap
joint stub ends, tubesheets, diffusion welded plate packs,
or flat heads to main shell, to formed heads, to transitions
in diameter, to nozzles, or to communicating chambers
any welded joint connecting one side plate to another
side plate of a flat‐sided vessel.

From what I'm getting from your posts is that something that would be a Cat B becomes a Cat C when any type of flange is welded to its end, but a Cat A stays a Cat A when anything is welded to its end. Is that correct? and where can I find this within VIII-1?

 

[r6155]

You are standing on UW-3 and you don't like to read UW in depth.

 

[Cobra17]

so please point me to the specific paragraph(s) in UW/VIII-1 that I should be looking. Isn't the point of these forums to help others understand? I like learning new things, and obviously I've misunderstood this portion of the Code. I know the Code has roundabout ways of explaining things, and often a simple specific reference can change a view of how something like this.

 

[gh61]

Are there any related sketch to your sketch in asme VIII-1 ?
tanks a lot

 

[r6155]

@ gh61
In your post (October 30, 2024) you mention UW-13.
It's been two months and you still haven't read Figure UW-13.1 (i).
Why?
You are very comfortable instead of studying.

 

[gh61]

@ gh61
In your post (October 30, 2024) you mention UW-13.
It's been two months and you still haven't read Figure UW-13.1 (i).
Why?
You are very comfortable instead of studying.

uw-13 is related to head and shell connection, but I need body flange to head connection

 

[goutam_freelance]

but I need body flange to head connection

See MA-1 Fig 1-6(Ed 2015)

 

[gh61]

See MA-1 Fig 1-6(Ed 2015)

See MA-1 Fig 1-6(Ed 2015)

I need welding neck connection similar to shell & head connection that shell replaced by body flange.

 

[goutam_freelance]

I need welding neck connection similar to shell & head connection that shell replaced by body flange.

Could not find it in the Code.

 

[r6155]

The weld neck flange hub is a cylindrical shell.

I'll stop here, there's no more time if you don't understand.

 

[Geoff13]

The Code Committee has a limited amount of time and resources, so they only include rules and sketches for "common" details. They could expand the Code to be ten times longer and still not cover every unique detail that someone might want to use.

The Committee recognizes this and thus includes paragraph U-1(a)(3) which notes "The Code does not address all aspects of these activities, and those aspects which are not specifically addressed should not be considered prohibited." Thus as long as the Code does not prohibit the detail you wish to use then it is permitted.

However since the Committee has not provided guidance on these other details they also included paragraph U-2(g) which notes "Where complete details are not given, it is intended that the Manufacturer, subject to the acceptance of the Inspector, shall provide details of design and construction which will be as safe as those provided by the rules of this Division." It thus will be up to you to provide this safety, and you may have to get the Inspector's agreement that you have done so. Given that your desired detail is very close to some Code details this should be easy.

Good luck