ASTM A403 Fittings - W vs. WX vs. WU

[AgsMyDude]

We have a client specifying A403 Class WX or WU fittings and I'm trying to understand the practical difference between these options and Class W, which is what our standard spec calls out. Based upon my reading of 5.4, 5.5, and 5.6, my understanding is that:

Class W requires radiographic examination of welds by the mill or fitting manufacturer if using filler metal (5.4.1) but not welds by the starting pipe manufacturer if not using filler metal. (5.4.2) If the fitting manufacturer uses fusion welding there are some conditions in which they can avoid radiographic or ultrasonic examination (5.4.3). Lastly the fitting manufacturer can also substitute radiographic testing for ultrasonic testing (5.4.4).

Class WX requires radiographic testing no matter what and Class WU requires ultrasonic testing no matter what. Although they both use the term "starting material manufacturer".

Questions:
Is "starting material manufacturer" the same as "starting pipe manufacturer" or the same as "mill"?
Where are the Class W testing requirements for welds made by the "starting pipe (or material??) manufacturer" if they use filler metal?
Where are the Class W testing requirements for welds made by the mill or that don't use filler metal?
Where are the Class W testing requirements for welds made by the fitting manufacturer or that don't use filler metal but also don't meet 5.4.3.2 or 5.4.3.3?

At the end of the day, I am really trying to determine whether (and why or why not) "Class W" is equivalent to "Class WX or WU".

Thanks in advance

 

[David3399]

Is "starting material manufacturer" the same as "starting pipe manufacturer" or the same as "mill"?

Yes

Where are the Class W testing requirements for welds made by the "starting pipe (or material??) manufacturer" if they use filler metal?

You answered this...5.1

Where are the Class W testing requirements for welds made by the mill or that don't use filler metal?

5.4.2

Where are the Class W testing requirements for welds made by the fitting manufacturer or that don't use filler metal but also don't meet 5.4.3.2 or 5.4.3.3?

If you don't meet 5.4.3.2 or 5.4.3.3 RT is required.

Table 6 may clear things up for you.

 

[David3399]

As an addition, your client is requesting welds be RT or UT no matter if there is filler metal or not.
W is only RT of filler metal welds and fitting manufacturer welds.
WX/WU is all welds, filler metal or not. (5.5 and 5.6)

 

[AgsMyDude]

Thanks, Table 6 was indeed helpful and we will stick with the client spec since Class W will not meet their requirements.

Just to confirm "starting material manufacturer" = "starting pipe manufacturer" = "mill" =/= "fitting manufacturer"?

 

[AgsMyDude]

I guess I would also ask in the case of Class W, why does it matter whether the weld is made at the mill or by the fitting manufacturer?

 

[David3399]

Just to confirm "starting material manufacturer" = "starting pipe manufacturer" = "mill" =/= "fitting manufacturer"?

Correct.

I guess I would also ask in the case of Class W, why does it matter whether the weld is made at the mill or by the fitting manufacturer?

I'd be lying if I said I knew for sure, but the starting materials are made to a specification as well, such as SA-312 which have there own requirements for example, hydrotesting/Eddy Current.