Filler metal size qualified (ASME)

Date 10-31-2005 15:42

I apologize if this is a dumb question; I'm trying to learn about WPS/PQR's and I have no previous welding experience. My question: per ASME IX, if a PQR is qualifed with 5/32" dia filler (SMAW process), is that the only size filler allowed to be used for the WPS? I've had several people tell me that I can go plus/minus 10% dia without requalification. QW404.47 appears to address this for LBW, but not SMAW. Any thoughts or advice would be greatly appreciated.

By chall

Date 10-31-2005 16:03

Begin by looking at the chart for SMAW (QW-253).

Diameter of the filler metal is addressed in the blocks listed QW-404.6 & .7. If you look, QW-404.7 is a "Supplemental Essential" variable. That variable only applies if the applicable construction code requires qualification of the WPS with notch toughness testing.

QW-404.6, which is a "Non-essential Variable" says: A change in the nominal size of the electrode or electrode specified in the WPS.

Since it is non-essential, you may change the information without the need to requalify the WPS. In this case, you would have to revise your WPS to include the additional information.

When we qualify procedures, we generally include information for the sizes above and below the actual size used for the PQR. We specify the manufacturer's recommended parameters.

Charles

By kedawhit (*)

Date 10-31-2005 16:12

Charles:
I follow your "logic" and it makes sense to me. If I'm understanding correctly, the whole issue of qualified filler size depends on whether notch tougness testing is required or not. That helps me understand how to interpret other areas where I have questions. Thanx for the response.

By chall

Date 10-31-2005 17:53

Whether or not requalification of a WPS is required, is determined by the classification of the variable (essential/non-essential, or when applicable, supplemental essential).

Sometimes though, details in the WPS, which may be non-essential, should be thoroughly considered before revision. Just because you may techinically change a variable, doesn't mean you should.

One example is this: Sometimes we limit the filler metal diameter because of the talent it takes to jump to larger sizes. We generally don't use 5/32" diameter E7018 on pipe (so the WPS may not lis it as an option). Some projects are staffed with our better welders who can handle that size. In those cases, we may issue a revision allowing the use of the larger filler metal. We would put the burden on the supervisor to make sure the welder can handle the electrode.

Charles