Using SB151-with ASME VIII div.I

[GIGI72]

WE are manufacturing a Cupro-Nickel Heat exchanger according to ASME VIII div. I -U stamped- and we have some problem to find S.O. flanges because the only flanges that we are able to find is made of SB 151-C70600, but this material is not permitted by the ASME VIII div. I, even if is included in the ASME II part B. Can someone suggest me a way to exit from this problem?, using the SB151 and not the SB171?
Thank You

 

[deanc]

IMHO

This is tricky. You need to speak with your AIA. SB-151 is a product form,the UNS number C70600 is the material and is what you need to base your argument on,as it is permitted in other forms. Case in point being SB-359(see App.23) tubes which in SecII are NP.

See UG-10,UNF-5,and UNF-15.

Don't know all the details of your application-however I would start here.

Oh yes-have fun.

 

[bmoorthy]

I would go for Weld over lay and get around the problem. This is what we did last time and AIA did not have problem. As for undiluted chemistry requirements, it is easy to convince the User (Mostly this CU NI) will be for Sea water service with a better and ASME Permitted Weld metal.

Good Luck and keep us informed as to how you solved your problem

 

[deanc]

Don't know if I would buy-off on a weld overlay--but ask.

Another one---do you have or could you hae a circ.joint weld before the flange? Put it outside the Code boundry.

 

[codeeng]

I'll go one step further than deanc.
Interpretation VIII-1-95-52 states that the designer may choose to exclude the nozzle from the requirements of Div 1 by defining the extent of the pressure vessel as the vessel to nozzle weld. As long as you're satisfied with the SB151 material then this would be the best solution.

 

[deanc]

codeeng:

Don't think thats what it says. Nozzle neck to weld neck flange and the joining(circ)weld. The nozzle neck and the attachmant weld to the vessel is still code. See U-1(e)(1)(a).

Still have to be careful-some jurisdictions go to face of the first flange.

 

[codeeng]

I'm quoting directly from CASTI Guidebook Volume 4 Chapter 2. I recall this came from someone wanting to use other flange standards (BS, Din, etc) with non ASME materials.

 

[deanc]

I have the actual interpretation. I quote:abbreviated

Interpretation:VIII-1-95-52
Subject: SecVIII Div1 1992ed 1993add U-1(e)(1)
Issued March 13,95
File: BC95-047
Ques:An Al WNF is welded to a nozzle neck of an Al vessel,constructed to the rules of SecVIII Div1.May the Manuf.exclude the WNF and the joining weld from the scope of Div1,ie.,U-1(e)(1),if they are properly described on the vessel drawing and the MDR?

Ans: Yes

As you can see the nozzle neck is attached to the vessel and the WNF will be attached to the nozzle by a circ. weld.

BE CAREFUL: Do not use a text for Code work-use the Code. Common mistake. Go back read U-1,the manuf.has a lot of latitude. Also remember Interpretations are not binding.

 

[jte]

I agree with deanc. See also Interpretation VIII-1-83-329. This would apply for example to a bottom outlet which has a 90° elbow and goes out of the skirt. The Scope break can be defined at the weld between the vertical nozzle neck and the elbow. That vertical chunk of pipe welded to the head is a Code component.

"Q: A nozzle for a piping connection to a Section VIII, Division 1 vessel consists of a nozzle neck joined by a butt weld to a section of pipe which is joined by another butt weld to a welding neck flange. May the vessel Manufacturer include the section of pipe and the welding neck flange in his construction, but exclude the section of pipe, the welding neck flange, and their joining weld from the Scope of the Code?

A: Yes. See U-1(e)(1)(a)."

jt

 

[GenB]

If flange is what you need, you may want to keep your cupper/nickel material intact by using a loose flange, or how is called, a van-stone flange! where the loose flange will be out of stanless or bronze...
ER

 

[bmoorthy]

That would be a Lap joint flange