Question about Welder Performance Qualification per AWS D1.6

Date 01-12-2017 11:54 Edited 01-12-2017 11:59

Per ASME, the issue is the thickness of the joint and the deposited weld thickness, not the number of layers or beads. The exception would be if there is a restriction on heat input the production weld where the travel speed, voltage, and amperage is restricted.

The welder taking the performance test must follow a qualified WPS, not the PQR. If that WPS has limits on the heat input, the welder must comply. However, if the WPS used for qualification had no restrictions on the heat input, the welder can use as many or as few beads as needed to fill the joint. The qualification is valid for production welds with or without heat input restrictions, with or without PWHT.

Once the welder is qualified, he must comply with the WPS used for production which may be different from the WPS used for qualification, If the production WPS imposes restrictions on the heat input or if there are limits on the size of the individual weld beads, the welder must work within the limits of the production WPS.

It is not uncommon for the WPS to include sketches of the permissible joint details. The sketch may include weld beads as representative, but only as a guide, not as a requirement for the number of weld beads that must be used.

Again, we are speaking about ASME Section IX requirements as supplemented by the requirements imposed by the construction code.

Best regards - Al

By jwright650 (*****)

Date 01-12-2017 12:22

"snip....the welded can use as many or as few beads as needed to fill the joint......snip" -Al

I agree with Al, but with one exception....maximum fill pass thickness and/or width should not be exceeded for the welding process being used. I don't remember if D1.6 has a Table similar to D1.1....although the WPS is qualified so those rules may not apply.

By 803056

Date 01-12-2017 12:57

My bad, I don't know where the reference to Section IX came from!

Since this WPS was apparently supported by a PQR, the restrictions for prequalification are not applicable. The table listing the essential variables for qualification does not include any restrictions on heat input or the number of weld beads or number of weld layers. There isn't even mention of the maximum interpass temperature. Interesting, keep in mind I grabbed the 99 edition of D1.6.

Al

By jwright650 (*****)

Date 01-12-2017 14:48

Thanks AL, I did not have a copy of D1.6 with me out here to look back at.

By Vincent Chiu Date 01-13-2017 01:30

Many thanks.
I only have code 1.6 1999 edition, Table 4.1S Overlay Essential Variables for all Processes item 2:10 mention that "A change from multiple layer to single layer, or reduction in the number of layers", So, this rule is only used to restrict the overlay variable of WPS qualification, it does not apply to welder/welding operator performance qualification?

By 803056

Date 01-13-2017 06:16

Yes, the table only addresses the requirements for cladding or overlays (surfacing welds). The table on the facing page, Table 4.1, applies to all other weld types.

Best regards - Al

By Vincent Chiu Date 01-13-2017 09:57

AL, thanks. But one more question... :lol:

D1.6 Table 4.2(b) states for the number of welds per that 1 weld test specimen for each position to be uesd.
In my interpret
If the PQR was tested in the "2F" position then the WPS is qualified for "2F" position only. Right ?

Thanks.

By 803056

Date 01-13-2017 13:26

We are still using D1.6:99 for this discussion. You didn't say you changed gears and are now using a more recent edition. Table 4.1 does not list position as an essential variable for the PQR. So, the WPS qualified for a groove tested in any position can be used for any position in production (refer to clause 4.1.7). There is an inconsistency in the table with regards to vertical progression. The WPS must be qualified for either vertical uphill or downhill progression. Table 4.2 does not include any additional requirements if the WPS is for a groove weld. However, the table indicates a WPS for fillet welds must be qualified in each position used in production. Clause 4.1.7 states the PJP groove, fillet weld, and plug and slot welds must pass the macro etch requirements even when the mechanical properties have been established by the groove weld qualification. One must be careful to read the text as well as the tables.

Table 4.4 addresses the range the welder is qualified to weld based on the test position. There are differences between performance qualification and the qualification of the WPS.

In this case, the mechanicals are qualified by the groove test. One test qualifies the mechanicals for all positions. However, the fillet weld must be welded in the position used in production and must pass the macro etch requirements. In summary, one PQR qualified using a grooved butt joint and fillet welded in each production position.

I see no provisions for qualifying the WPS for fillet welds exclusively. The mechanicals must be verified by welding a grooved test assembly, either plat or pipe.

At least that is the way I read the requirements.

Best regards - Al

By Vincent Chiu Date 01-16-2017 08:50

Thanks