ASME IX WPS Joint Design Clarification

[BCbrad]

Hello,

I am hoping I can get some help understanding the joint design details required on a WPS using SMAW with a groove weld.

What details are required in terms of the root spacing, land, bevel, backing, etc?

QW-253 shows all nonessential, so does that mean that a WPS with an illistration of a groove joint is sufficient? If not, where can I find the governing factors with the specific information?

Thanks.

 

[gtaw]

You can use the prequalified joint details depicted in AWS D1.1 for a starting point.

You can also refer to a number of AWS D10.X recommended practices for pipe joints. An example of one of the D10.X RP is AWS D10.12 Recommended Practice and Procedures for Welding Plain Carbon Steel Pipe.

Best regards - Al

 

[stanweld]

You can also refer to joint designs in piping codes and ASME Boiler and Pressure Vessel Codes.

 

[BCbrad]

Thank you both for the reply. But in terms of a QW-282 the root spacing or bevel angle do not need to be spcified ot illistrated.

 

[Fizza453]

In this case, I would show a nominal sketch groove weld on the WPS and would add a note "follow the joint detail as per relevent drawing(s)".

Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[gtaw]

ASME code sections are not "how to" codes. Weld details such as root opening, groove angle, groove type, etc. is pretty much left to the engineer's discretion. There are several prohibited joint details in several of the construction codes, but again, little in the way of specifics. You can reference B16.25 for a couple of typical pipe details, but there is nothing specific relating to vessels.

The information needed by the welder to properly fit-up the weld joint are typically considered to be nonessential variables. That means the engineer can change them without having to requalify the welding procedure, but that doesn't mean the information doesn't need to be provided to the welder. While ASME codes provide the engineer with considerable latitude, it doesn’t mean the engineer doesn’t have to address the problem and lay it all at the welder’s feet with a comment like, “You’re a welder, you should know this stuff.” That’s a cop-out by an engineer that doesn’t know what he/she is doing.


Best regards - Al