WPS for base metal restoration. Prequalified??

Date 04-15-2009 13:05

I have a project where the root gap of CJP beam to column connections exceeded the 'as-fit' tolerances of the TCU4a figure 3.4. My firm has prepared a standard AWS format WPS to instruct a welder how to restore the beam length to within an acceptable root gap dimension before joining the two members. Our WPS uses the term 'buttering' of weld metal, while addressing the other parameters of a WPS including references to base metal, filler metal type and size, preheat, etc.. In accordance with our project specs, we submitted the repair WPS to the Engineer of Record. He has rejected the WPS stating the WPS requires qualification in accordance with D1.1 Section 4-Part B.
The WPS incorporates all aspects of Section 3 to meet the prequalified status. My opinion is the repair of root gap dimension is simply an application of the WPS and does not require qualification. Any other opinions??

By hogan

Date 04-15-2009 14:17 Edited 04-15-2009 14:21

Can you list what your wps states as the root gap, your tolerance, and what the actual gap is? Look at AWS D1.1 (08) 5.22.4.3

By 803056

Date 04-15-2009 17:19 Edited 04-15-2009 17:25

Maybe this is one of those issues open to debate. Clause 5.22.4.3 of AWS D1.1-08 permits the correction of the root opening by welding provided certain limitations are not exceeded. If the root opening exceeds the limitations the root can be corrected with the engineer's approval per clause 5.22.4.3.

The correction of root opening variation for machine and automatic welding is addressed by clause 3 which deals with prequalification. Root opening variation is permitted (or required) by clause 3.11.3. There is no mention that the WPS used for the correction be qualified by testing per clause 4.

The reason to reduce the root opening is to reduce the total contraction in the joint to something that can be tolerated without causing cracking problems. Assuming the weld metal matches the properties of the base metal and is sound, I don't see a problem with restoring the base metal by welding.

There is no special testing requirements in D1.1 for surfacing, buttering, overlays, call it what you might like. What specific testing does the engineer ask for?

Best regards - Al

By blanier (*)

Date 04-21-2009 17:01

Thanks Al, the engineer in this case is surprisingly informed in D1.1 compared to most building structural engineers I've dealt with in the past. His contentions is that D1.1 prohibits considering a written WPS for correction of root gap (to within the tolerances allowed to come into compliance with one of the commonly used 'prequalified' WPS such as TCU4a)to be prequalified and then falling back onto the standard prequalified WPS. His opinion is that the two WPS being used constitute a new combined WPS requiring qualification as referenced in Section 4.

By Duke

Date 04-22-2009 02:37

EOR's opinion is the one that counts.

By blanier (*)

Date 04-21-2009 17:07

Thanks 'Hogan'. The WPS does not give an existing root gap, only that the excessive gap caused by some fabrication or drawing error has to be closed to within the gap already specified by the original joint designation. The actual gap stated in our WPS is limited to 'no greater than 1 inch'. In reference to 5.22.4.3, I recognize I am stating parameters greater than the 3/4 inch and thus one reason why we created the WPS. This WPS was submitted to the engineer on that basis and as contained in the next paragraph, 5.22.4.4. The original issue is resolve as we designed an alternate connection but having some opinions or conclusions of my peers is now the objective.

By 803056

Date 04-21-2009 20:24

In this case the engineer is holding all the high cards and the check. The saying is, "He who holds the gold makes the rules."

I guess it applies in this case.

Best regards - Al