Does anyone know of any AWS training classes in writting / maintaining WPS's / PQR's?? I am looking for a better understanding of how to write a better WPS, that is compliant with D1.1 code. I sometime run into others who are either less educated or perhaps better educated than I am in writting / reviewing them. I end up revising them often to make a customer happy, only to completely re-write the wps for yet a different customer. It seems that some of the requirements for WPS's are too wide open for interpretation.
I have some customers who adimantly insist on the electrode brand and trade name, not just the AWS classification and specification - for a prequalified procedure using GMAW. I have others who are insisting that current range on my WPS match exactly - the electrode manufactures acceptable "current range". To me this sounds crazy, considering that this range runs from short circuit transfer all the way up to spray transfer, and utilizes different gas mixtures across the board.
I have seen companies use a "job-specific" welding notes or addenda to address customer comments without the need to revise the WPS for each customer. The WPS usually has a note requiring the user to refer to the job-specific welding notes prior to using the WPS. Could be an option for your issues.
"I have some customers who adimantly insist on the electrode brand and trade name, not just the AWS classification and specification - for a prequalified procedure using GMAW."
I run into things like this too, where customers are simply ignorant of the requirements. Usually a diplomatic discussion with the decision makers is all it takes to convince them of their error. Sometimes however we run into CWI's who may be contracted by the company to review WPS's and they just can't be wrong, ever. They get something stuck in their head and walk around incorrectly quoting the D1.1. Myself I like to look things up, even if I think I remember it.
As a CWI myself I find it difficult when I have to explain to a customer why their CWI is wrong.
If there isn't such a class there should be. I'd sign up for that one in a heartbeat.
By jwright650 
Date 09-29-2010 11:44
Edited 09-29-2010 11:52
There is also the seminar coming up at the FABTECH Welding Convention in Atlanta in Nov, 2010. I think on the 3rd is one on How and Why of WPS's.
Have a Great Day, Brent
What you have described is common. Very often, the customer's reviewer has some idea, whether right or wrong, as to how they think a WPS should be written. It can be frustrating to put the effort into it so that you know That the WPS is realistic and covers the code requirements - then you get it back with "revise and resubmit".
Maybe I shouldn't feel this way but it is much easier to simply let the customer have it his way. I make the changes and keep the originals and all comments for my files. Of course, if the request is totally in error I politely protest it and sometimes the reviewer agrees with me after we talk about it. But overall it isn't worth the argument. That's why we end up with a "cookbook" full of WPS's -each one has a slightly different "flavor".
I just received the Oct/2010 edition, volume 13 no. 4 of Inspection Trends. There is an article written by one of our forum members Al Moore that covers Qualifying of WPS by Testing...it is a good read, and covers some of your questions regarding WPSs and PQRs.
http://www.aws.org/itrends/2010/10/IT_October_2010/
Electrical parameters on Prequal WPS are limited by table 3.7 (prequal requirements) which states within Mfg's recommended ranges, but also by table 3.8 (Prequal Variables), which states:
+/- 10% on Amps
+/- 15% on Volts,
+/- 10% on WFS
+/-25% on travel speed.
Long story short, you have to all of your +/- ranges fit within the % window as well as within Mfg's range.
For Qual by welding, the code does not mention Mfg ranges, and the voltage range goes to +/- 7%, all other ranges the same as above
"He who holds the gold gets to make the rules."
I may have miss quoted, but the idea is the same. "The customer may not be right, but the customer is never wrong," tells it like it is. There are times when you bend to the customer's requests even if you do not agree with them as long as they are not in violation of a code requirement or something that is simply unethical.
CWIs, that is a different situation all together. There is nothing worse than a CWI with a God complex. As mentioned, some CWI's believe they are never wrong. If the CWI works for the customer go back to paragraph one and two, if the CWI is a TPI, step back because the fur is going to fly.
There are plenty of situations where there is room for disagreement because the code cannot possibly address every conceivable situation that can crop up on a project. There are times when a meeting of the minds is necessary and a civil discussion of the code requirements is needed. When there is a situation that cannot be resolved by mutual agreement, it is time to let the Engineer step in and make a decision. It is not up to the CWI to interpret the code or make decisions that require the Engineer's input.
Best regards - Al
Tell them that the trade name is not a requirement and that any changes made will be a backcharge. See how that grabs 'em. Or go with the flow, make the changes and toss the modified procedures when the job is over and go back to your "correct" set.
I see this all the time, and in fact I am sometimes the instigator. It is true that D1.1 does not require the manufacturer and trade name of a GMAW electrode to be listed on a prequalified WPS. However, 3.7 of D1.1 states that all requirements of Table 3.7 have to be met for prequalified WPSs and Table 3.7 requires that for GMAW the current be within the range recommended by the manufacturer. When I as the owner's representative see a prequalified WPS and I ask the question about which manufacturer and trade name they are basing the WPS on, they usually have this correct (i.e. they tell me which electrode it is and the WPS accurately reflects the manufacturer's recommendations). When I ask how their people in the field will know which electrode the WPS was based on, most of the time they agree that there is no way to know if the WPS doesn't provide the information and they volunteer to list the manufacturer and trade name on the WPS in order to avoid confusion. Personally I don't see the problem. It may be a small issue because there are usually not huge differences in manufacturers' recommendations for a given electrode, but I have seen that some differences do exist.
Mankenberg
Kip makes a good point.
I am very specific when I write a WPS for FCAW. There are differences in the recommended ranges for the parameters from one manufacturer to another, even if the electrode is the same classification.
Best regards - Al
