Nozzle to Shell Weld

[IdanPV]

Hello all,

I have a question regarding a nozzle to shell welding in an ASME "U" vessel.
The weld detail is similar to that shown in ASME VIII-2 Table 4.2.12 detail 3/ASME VIII-1 Figure UW-16.1(z-1) except that there is no bevel in the shell, and the shell is completely straight.
See illustration below (ignore the "tc" marking please)


1. Is this kind of weld detail is acceptable?
2. What would be the correct symbol for this weld as per AWS and ISO.

Thanks,

 

[pvros]

Hi,
1. in edition 2023 of code i see a different detail. Note that figures UW-16 are "some acceptable...", not mandatory. Even if i never seen square groove weld, in particular in shell to nozzle joint, any detail as long as it is qualified with a dedicated PQR should be acceptable.
2. google "square groove weld".

 

[IdanPV]

Thank you @pvros.

1. Edtion 2023 do contain differnet "acceptable" details, with bevel, and I am looking for a square groove as you said.
2. Note that this is a combination of groove and fillet, and I did search for "combination groove and fillet weld symbol" and also looked in AWS A2.4.
I was only able to find "bevel-groove and fillet weld symbol".
The only thing which seems to be acceptable for my case is AWS A2.4, Figure 6.3 (D), however, it's not realy my case.

 

[pvros]

I agree that you may use 6.3(d), just drafting half of the symbol.

I'm a bit perplex you are using an "uncommon" weld detail that you even did not know how to indicate, but again, if you are able to qualify it...

 

[IdanPV]

I understand where this comes from.
Typically, we use a fillet weld from the outside only, as permitted by UW-16(f)(3).

However, due to manufacturing constraints, we now need to modify this approach.

Adding a chamfer or creating an angle in the shell to fully comply with Figure UW-16.1(c), (d), or (z-1) increases production costs and adds some complexity to the process.

 

[Trestala]

Don't know what the thickness of those parts is, but you are essentially doing a weld buildup with that configuration.

 

[IdanPV]

Shell - 5mm
Nozzle - varies from 4 to 5.5mm

Question is does it mandatory to create a chamfer in the shell or it is permitted to leave it straight.

 

[Trestala]

Question is does in mandatory to create a chamfer in the shell or it is permitted to leave it straight.

What is the gap between the shell and nozzle? Does the gap meet the requirement for the welding process you are using? How are you going to fit-up the nozzle? Are you meeting are the parameters in your WPS/PQR?

 

[IdanPV]

Thanks @Trestala, I will try to share some more information:
1. The gap between the shell and nozzle is about 2mm.
2. The WPS I want to use doesn't fit exactly because it includes a chamfer in one of the parts, however, as per ASME IX, Table QW-255, changing the Groove design for GMAW welding is define as nonessential variable.
3. Fit-up the nozzle will be made using tack welds (UW-31(c))

 

[Trestala]

@IdanPV, thanks for the detail. Not really sure of the specifics of ASME IX regarding that, my only concern if you would really be able to achieve full penetration with a square joint and 2mm gap that is 5mm deep. A bevel would usually be applied for better access to the root of the weld.

 

[IdanPV]

Thank you @Trestala.

We decided to do a mockup and see if it's achievable.
If we will find out that full penetration can't be achieve than we will do a bevel.

 

[DekDee]

Just remember the code stipulates minimum requirements (eg. bevel requirements are deemed non-essential).
If your project documents require CJP for that joint it is up to you to provide CJP - however you see fit.
The diagram you have posted is not condusive with CJP - definitely not recommended