Is there a connection like UW-13 for direct connection of Body flange to spherical heads? 2

[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.