The code lists the minimum information required by the PQR, WPS, and the performance test record. Often, the minimum required information isn't all that useful in the long run.
I record all the information I can so I have a resource I can use in the future. For instance, the PQR must record the essential variables. Information such as arc voltage, wire feed speed, amperage, electrode extension, travel speed are not considered to be essential variables. Likewise, the electrode specification and classification are considered to be nonessential unless CVN is required.
Both the essential and nonessential variables are required to be listed by the WPS. This where it gets interesting. Several times a year I have contractors asking me where they go to get the welding parameters to list on the WPS? I ask them what were the parameters when they welded their test coupon? Their typical response is, "We don't have to record the nonessential variables while welding the test coupon." They are correct, but now they need that information to complete the WPS.
ASME is one of the few codes that will allow you to write a WPS that is totally useless if you subscribes to the philosophy that the WPS should provide useful information to the welder. After all, isn't it one of the primary purposes of the WPS to information to welder to enable him to make a weld that has the mechanical properties required by the code?
FCAW is an interesting welding process. The selection of welding parameters is very dependent on the specific electrode classification used. The success of the welder is strongly influenced by the use of the proper arc voltage, wire feed speed, and electrode extension. If the welder uses the wrong electrode extension, there is going to be issues with welding defects. The proper electrode extension is a function of electrode diameter and wire feed speed and to a lesser extent, arc voltage. Welders often fail to pay attention to the WPS for one practical reason, all too often the person writing the WPS is clueless of how important the correct welding parameters are. Once the welder questions the validity of the welding parameters provided, the WPS is disregarded and the WPS is a failure.
There are seminars available the provide instruction on the subject of qualifying WPSs and writing WPSs that are code compliant and useful to the welder. I saw a seminar listed under the heading of Educational Opportunities in the AWS Welding Journal.
Best regards - Al
