My suggestion is to develop a "preliminary" WPS to provide direction to the welder for welding the test coupon. The preliminary WPS is nothing more than a WPS that has not been tested and is your best guess of what will work. Review the welding standard you are working to and follow their lead as to what has to be addressed in the WPS. Write it up, identify it as the PWPS and give it to your welder. Have the welder follow the PWPS listing all the variables, i.e., process, base metal, thickness, groove details, filler metal, diameter, position, voltage, amperage, wire feed speed (if applicable), etc.
When the welder is ready to actually weld the test piece, monitor the actual welding and verify the proper welding paramenters are utilized. By that, I mean independently verify the groove details are as indicated by the PWPS, the proper base metal (with supporting material test reports) is used, the proper filler metal is used, and the welder is staying within the prescribed voltage, amperage, travel speed ranges, etc. as specified on the PWPS. I point out that the test should be monitored because I've reviewed many Procedure Qualification Records (PQR) where the contractor stated the welder monitored the voltage, amperage, travel speed, etc. and entered the values on the PQR when I ask where the values listed on the PQR came from. For most cases, that's a pretty neat trick if you consider the difficulty the welder would have simultaniously watching the gages or meters on the welding machines (or multymeter) and use the stop watch to record the time each pass took so the travel speed could be determined, and all other necessary information while the welding hood is down and the weld is being deposited. Then again that may explain why the welder couldn't stay in the weld groove, but I digress.
Once the test sample is welded, perform the necessary visual examination of the completed weld and any additional NDT required by the welding standard. Cut up the test sample as per the requirements to remove the required samples for destructive testing, i.e., bend and tensile samples, and impact samples if Charpys are required. Note: if you happen to be working to ASME requrements, check with the applicable construction code, i.e., Section I, Section VIII, B31.1, etc. to determine if and when Charpy impact testing is required.
Record the results of all NDT and destructive tests on the PQR. Don't forget to sign the dotted line. If the services of outside laboratories are utilized, I recommed you attach copies of all supporting documents, i.e., material test reports, NDT reports, destructive testing reports, etc. to the PQR package.
Once the welding procedure is qualified, i.e., the test samples all pass and the requirements have been met, you formulate the WPS to be used by the production welders. Depending on the welding standard you are using, the ranges listed on the qualified WPS (used by production) are somewhat different than those used by the welder that welded the test sample used for qualifying the WPS, however, the actual values (used by the welder) and recorded by the test witness on the PQR while welding the test sample is an excellent basis of deriving the ranges for voltage, amperage, etc. to be listed on the WPS. Some welding standards (codes inclusive) limit the range of the voltage, amperage, wire feed speed, travel, etc. as a percentage above and below the values recorded on the PQR, so it is important they be a true representation of what was done while welding the test sample.
Most welding standards that address the qualification process also include sample forms for the PQR, WPS, and WPTR. They can be used as a format or you can develop your own. I have my own formats because I include more information than can be recorded on the samples provided by most welding standards. My philosophy is that the WPS may be the only work instruction the welder has access to. That being the case, the WPS should list everything the welder needs to know to produce a "code" complient weld. That includes groove details and tolerances, fitup requirements, and perhaps even the acceptnce criteria. If the company has other work instructions for the welder's use, then thoses bits of information do not have to be included in the WPS, but they (the work instructions) can be referenced.
I hope this helps.
Best regards - Al
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