Paul 3

Good question.  Its about time someone asked it. I wasn't going to respond to this string, until you asked the obvious question.  Here is what I think a weld map is.....

In my experience a weld map was a record of all the welding and material information on each joint in a structure.  It included a line drawing of the piping, elevation and grid map of each joint, WPS used, welders involved, who did the root, who did the fill and cap passes, Filler Metal used, Heat Numbers of the weld metal and the base metal, Etc.  On the PV, it showed the preheat record, the limits of where each welded started and stopped, the radiograph numbers, Inspection and NDT notes per segment and joint.  There was also a record of the pertinent information on the bolts and installation information.

I heard a story of a large nuke power plant manufacturer / erector offering the weld map to a nuke power plant owner at the end of a job, (for two million dollars) and the utility owner declining to buy it.  Ten years later when the in-service problems and repairs began to mount up, the utility regretted this decision.

It was speculated, that if they had the weld map, they would not have had to re-radiograph all the welds of a given type when a "welder type" defect was discovered during in-service checks.  They speculated that they would have only been required to check the welds performed by that welder.  They also had corrosion type problems as the plant aged.  The engineer speculated that knowing if one pipe manufacturer was involved could have limited the scope of testing.  In-service after the plant was hot, testing is very complicated and expensive.

I have kept this type of information to a lesser degree on an urban cross country gas pipeline (TETCO Facility Main extension in Brooklyn NY), as part of my daily inspection report.

I have also kept this type of information to some degree on bridge girders and all Fracture Critical Bridge member fabrication, including pass by pass detail, as part of a daily report and member "follower form".  I routinely maintained a Material Record for each member, including the MTR Numbers and heat numbers for each member and component of the members, (I.E. Stiffeners, and Connection Plates), (direction of rolling) and heat numbers, and serial numbers for the electrode and the bags of flux.  You can almost touch any part in the structure and trace all the way back to the shovel of ore the metal came from.

On all these "Weld Maps", I have routinely signed them off or initialed my portion of the forms as appropriate, when I was the inspector of record.  This is all routine QA inspection reporting to me. 

Compilation of a comprehensive, easy to review, compartmented map, at the end of construction would require pre-planning, and indexing for easy reference.  That is where the extra money would come into play, because on a large job this activity involves extra time and manpower.

While I am still not sure what was originally meant by the words "weld Map", this is what I think it means.

Joe Kane

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