I figured my response would stir the pot. We haven't had a really good discussion going for a couple of weeks. I thought it was time to see what other people have to say on the subject.
I get tired of trying to have an intelligent conversation with the idiot in the mirror. This is the place to go to get a good feel for what's happening in the real world.
I understand where Henry and Gerald are coming from. I tend to agree that the "suggested" formats or the sample formats included in the codes are insufficient for the job intended, but I also understand that they can be a useful starting point for someone without experience in writing a WPS. I stopped using the formats included in D1.1, B2.1, or ASME Section IX long ago. I've had “Welding Engineer Wanabes” go into hysterics because the format I elect to use isn't what they are accustom to seeing. I have one shipyard that is attempting to have their vendors use a "cookie cutter" format because it makes their job easier. While I understand their consternation with having to deal with multiple formats, they tend to forget the WPS is written for the welder, not the engineer that is reviewing it.
I have reviewed WPSs that used a “narrative” to address the issues encountered by the welder on every job, items such as precleaning, interpass cleaning, cleaning the completed weld, electrode storage, etc. They are used to “support” a “technique sheet” that most of us would recognize as the WPS.
Other companies adopt a system of WPSs or a series of WPSs for each joint configuration. They provide their welders with a thick notebook/binder with all the WPSs that are used on the current job or the next. It becomes a paperwork nightmare when it comes time to revise an individual WPS because they have to make sure the old WPS is removed and replaced with the latest revision.
Some of my clients that have entered the computer age have all the WPSs on the main frame where they can be accessed and printed out by the welder when they are needed.
What’s my point? I’m not sure there is a point other than the fact that the person writing the WPS has to have an understanding of what information is needed by the welder while still complying with the applicable code. I’m sorry to say there are few engineers that understand or take the time and effort required to understand the customer’s needs. That customer should be the welder. The welder is the end user even if he or she isn’t signing the check.
I’ve encountered many cases where the consultant turned over the welding documentation to a client with little or no explanation of what it is, how to read it, or how to use it. It isn’t enough for the “consultant” to know what the information means, the client also has to understand what it all means or it becomes more paperwork containing nothing but more useless dribble. Blindly filling in the blanks on the “cookie cutter” forms may satisfy the person that doesn’t have to use them, but they provide little if any useful information to the welder.
The WPS should promote consist results on the production floor. The proof that the WPS is being read and followed is to go to the production floor and ask the welder where are the WPSs? It will amaze you how many don’t know the answer. Then ask the welder a few simple questions to see if he even knows where the information is listed on the WPS or what it means.
Let’s be clear, I am not shooting my barbed arrows at ASME alone. Many of my comments apply equally to all of the welding standards we encounter, but ASME is so easy to shoot at because it offers the largest target. That being the case, let’s query the welder.
The WPS lists the P number for the base metal. The question to ask is, “What is the P number of the material you are welding? Another question might be, “This length of pipe is marked as a meeting ASME A312 type 321. What is the P number and which WPS is used to weld it?”
Filler metals are listed by the filler metal specification. The question to ask is, “What electrode are you using? What filler metal specification does it meet?”
The joint detail lists “All grooves and fillets”, so the question to ask is, “What is the groove angle of that butt joint you’re welding and what is the tolerance?”
The welder is using a SMAW electrode and the weave bead technique is being employed. The question to ask is, “What is the maximum width of the weld bead using that particular electrode and what is the range for the amperage for the diameter being used?”
The list of questions goes on and on and the responses from most welders will be depressing if they have nothing more to refer to than an ill written WPS. Is it no wonder many welders simply chose to ignore them? In too many cases it is fortunate they do ignore them.
The last question to ask your self is, “Does the information contained in the WPS meet the intended objectives or does it fulfill its intended purpose?” If the honest answer is no, it doesn’t because the WPS isn’t in a format the welder can use or it doesn’t contain the information the welder needs, it serves no useful purpose. Someone wasted their time and money on more useless paperwork.
Which is more difficult to work with, AWS or ASME? From the welders standpoint, the WPS written to meet AWS D1.1 requirements will provide more useful information to the welder than one written to meet ASME Section IX and the associated construction code, i.e., Section I, Section VIII, or B31.X. Notice I haven’t said anything good about the AWS SWPSs.
Which one is more expensive to work with? Based on the fact that for the most part the contractor will have to go through the exercise of qualifying the WPS, while AWS D1.1 utilizes prequalified WPSs, ASME is more expensive.
Which one is more stringent with regards to acceptance criteria for visual and other forms of NDT? In general you will find AWS criteria more stringent, particularly if fatigue or cyclic service requirements have to be met.
Which code is more stringent with regards to welder qualification? Hands down, no question about it, AWS D1.1 is more stringent than ASME Section IX when bend tests are used to evaluate the soundness of the test coupon. Consider the following:
Undercut – AWS D1.1 - 1/32 inch ASME Section IX – not addressed
Face Reinf. – AWS D1.1 - 1/8 inch ASME Section IX – not addressed
Root Concavity (single sided groove welds)
AWS - 1/16 inch ASME – not addressed
Bend tests – AWS nothing larger than 1/8 inch plus the sum can’t exceed 3/8 inch
ASME – no single defect larger than 1/8 inch, no limit on total number of defects.
Which code is better? There is no “better” code from the welder’s standpoint nor from the inspector’s standpoint. The code is what the code is. We, the minions in the trenches, are simply tasked with meeting the applicable requirements. Give us a WPS that helps us do so in a meaningful way.
Best regards – Al
Why do you think I quoted "During welding, the maximum temperature of the base metal shall not be greater than 600 degrees F"
I agree that the WPS is written for the welder, but it is also written for the engineer, inspector or whoever is assigned to review the WPS.
He needs information about preheat, interpass and filler selection amongst other things...PWHT comes to mind.
I am often on projects with high temperature materials, USC boilers.
Very often my client has restrictions on the things I mentioned above, not because he has stocks in the required filler material manufactor, but because he has tested this particular rod/wire.
Another thing is, as part of the welders qualifiation test, he should also be tested in his general knowledge, including how to read a wps!
Before any welder on a project where am the responsible inspector even strikes the arc on P91/92 or X20 he has passed a small test, including how to read a specific test.
If a welder cant read and follow a WPS, he should not be welding. I honestly think that it is a very fair requirement.
3.2
It goes back to the idea of a well written WPS that provides meaningful information to the welder.
As for the quote you included, "During welding, the maximum temperature of the base metal shall not be greater than 600 degrees F." I had an inspector reject one of my welds based on a similar requirement listed in the WPS. I handed my welding hood to him and told him to bring out the hot glue guns because there would be no more welding on that project.
He looked totally astonished and blubbered something incoherent. Something about his demands being totally in line with standard practice, blah, blah, blah!
Well, let's step back a minute and tell the story from the beginning. I was happily burning rod when "Numbskull" comes along and sticks his "temperature indicating crayon" into the weld crater of the weld bead I just finished. The slag was still soft. The end of the crayon melted and started to burn.
"What the hell are you doing? What kind of Jackasx are you?" You could tell we really hit it off and were soon to be "best friends".
"I'm checking your interpass temperature!" was his reply, "And you're way over the maximum IPT of the WPS!"
"No shxt!" I shot back!
"This weld and all that you've welded are rejected!" he sputtered.
About this time my "helper", a veteran of the Vietnam conflict who spent 18 months in the hospital at Portsmouth, NH took notice. "What's this dumbasx saying Al?"
"He just told me you and I have to cut out all these welded moments because I exceeded the IPT!" I said with a wink and a smile.
"Really?" was all he said. Looking at the inspector he said, "Come over here you pipsqueak! What's all this about?"
"We can't do anymore welding on this building, get the rest of the welders down here so we can get our money and hit a different job!" I told him.
"OK, I'll go get em!" he said.
Now the inspector is starting wonder what he did wrong, why are all the welders being called down, why are they all laying down their shields, am I going to get killed? The last question wasn't entirely unreasonable.
When everyone was gathered around I told them what had transpired and that we couldn't do anymore welding.
"I never said you couldn’t weld, I just rejected all your welds because you exceeded the IPT!" he explained.
I said, "How did you measure the IPT?"
He described what he did and there were a few murmurs to be heard from the group.
Then I asked the welders how hot did the metal have to get in order to make a weld?
"Damn hot", was the response.
I said, "You’re right, we have to exceed the melting point in order to obtain fusion and that is going to be well over the IPT every time!"
Everyone except the inspector was laughing. He says, "But you can't exceed the IPT listed on the WPS."
Then I asked, "When do you measure the IPT and where do you measure the IPT?"
Several of the fellas replied, "Off to the side of the groove next to where the next bead is started and just before striking the arc!"
"Right! My welder know when and how to measure IPT, why don't you?" I shot at the inspector.
We all went back to welding and the inspector learned how to measure IPT.
The only welding standard that requires the welder to know anything more than how to run a bead is NAVSEA TP248. TP248 requires any welder that welds on Navy "stuff" to pass a written test before striking an arc. It is a great idea and you have my full support on that issue. However, it isn't just the welder that needs to be trained, the inspector, designer, and the engineer need to understand the fundamentals of welding just as much as the welder does.
Best regards - Al
Yes, the inspector must also have good skills.
Many inspectors are often put in positions, where they should not be.
One of my questions in my little test is the welder has to select a WPS for a given weld, I give him 3 different to chose from and 99% of the welders chose the correct one, that tells me that it is not that difficult.
I have also seen some contractors re-write their WPS' into a "welding instruction" where they have deleted all the kj and PWHT requirements......cool idea.
However, I also require that the welder has the original WPS during welding as I sometimes perform "production examination" in order to assure correct heat input.
3.2
Al
I am sure glad you stirred the pot, Made me contemplate more,
Thank You
That's the goal of the Forum. It is a place to discuss ideas and make each of us think a little more about how we approach everyday problems and once in a while we even agree on things.
Best regards - Al ;)
Well said Jon! There's way more to working, and welding qualification, or other equally important factors via ASME than just Section IX! ;) It's too bad that many are misled into thinking otherwise IMHO! ;) Always Sometimes Maybe Eventually = ASME! :) :) :)
