I have been given a WPS to review, to join .500 wall pipe to 1¾ A572 Gr. 50 plate. the WPS does not identify the pipe material, other than "80 KSI, Typical .29C, .27CR, .17CU, .99MN, .22Sl-Ni...
(not sure about the Sl-Ni, my copy cut off after the 'N') they want to use E71T-1 T-9.
The WPS indicates that "welding electrode is undermatched per discussion with Lincoln Electric engineer. This will help the HAZ from cracking, because the chosen electrode is better suited to the parent metal. this is not an AWS prequalified material. (CE=.565)"
So, I asked them to provide a PQR, and identify the material. This weldment is a bearing plate joined to permanent casing for micropiles. They did not specify whether the '80KSI' is yield or tensile. My wild assed guess would be tensile.
I'm really at a loss as to why they want to use this pipe, the plans call out A500/B RHSS, which would put them solidly into prequalified. I also questioned the deviation from material requirements.
My question is, qualification of a fillet WPS provides no quantification of tensile strength... I would really like to see this get pulled, am I out of line to ask for qualification per 4.11.3, I'm not sure about 4.11.3 (1) if "the welding consumables do not conform to the prequalified provisions of Section 3". E70 would seem to match the grade 50 plate just fine.
Their reference standard(s) are AWS D1.1-2004, 2006; but they wrote this thing about 10 days ago.
They are going with a min 350F max400F PH/IP temp, with a 400F cooldown in a blanket for 2 hours.
Any comments would be appreciated.
One more thing... when they talk about "may not be suitable for dynamically loaded elements in welded structures, etc., where low temperature notch toughness properties may be important" how low are they talking about? - From ASTM A500-03 scope, Note 1. ...Just trying to figure out why they don't want to use the specified material. These joints will be inside concrete, in a basement.
I have encountered something like this a few years ago. The pile drivers like to use pipe that doesn't meet spec to save money.
Let me explain; the specification for piling is very loose, no chemistry, just a minimum tensile and yield requirement (if memory serves me). So, the contractors purchase lengths of pipe material that failed to meet the specifications under which they were made. The mill is left with a mountain of "scrap" that can't be sold to their original customer. The opportunity to sell the "out of spec" pipe to a pile driver is seen as a total win for the mill because the alternative is to sell the material as scrap. The pile driver contractor sees it as a win because he gets it at a firesale price and it complies with the piling specification.
The job I was involved with turned into a nightmare. The pilings were delivered to the site in 60 foot lengths consisting of several short lengths spliced together. The project manager noticed the splices looked questionable so UT was requested. The butt joint splices were indeed less than complete joint penetration so the piling contractor was required to repair the unacceptable joints. The piling contractor was requested to provide the project manager with copies of the WPSs. The piling contractor's response was, "What's a WPS?"
As you can imagine, it was all downhill very quickly. I was retained to witness and document the contractor's efforts to qualify the WPS. The pipe material they were using turned out to be drill casing that was "out of spec". The supplier wouldn't certify it to anything, it was "out of spec" end of story.
I had a chemical analysis performed on a representative sample. The chemistry was similar to an AISI 4130 composition. Long story short, welding each test coupons took about eight hours rather than one hour as expected by the contractor.
"I'll go broke on this project if I have to preheat and clean every weld bead! We never use complete joint penetration welds. We lay in a couple of beads and move on. I'm loosing money if it takes more than an hour per splice!"
The welds were like glass.
I told the contractor it could be welded, but not the way he was doing it.
"I've never had a problem before!" he screamed. "I'm being hosed for no reason, no one requires this!"
I have no clue what the end results were. The contractor certainly didn't want to do what I proposed to weld the pipe, so I recommended he simply scrap the pipe he had and purchase some weldable material. I said my goodbyes and had to turn the account over to a collection agency to collect what was owed for the testing.
Best regards - Al
I rejected the WPS, the drawings are pretty clear on material requirements... "tubing shall be ASTM A500 Grade B"
I really do get way too wound up over this $#!+
Good move, the right move.
Al
just curious as to what the pile spec called for. But, based on what your discription says, your call was justified.
I do not recollect the specification. The project was several years ago and I don't usually get involved in pilings.
It was interesting because the contractor selected the filler metal and the welding parameters, including preheat, based on the procedures they typically used. It was my fault when things went to hell on a hand basket even though I told him I didn't think the filler metal was the correct and the preheat was insufficient based on the chemistry of the pipe.
He said there was no reason to pay for a procedure that did not pass. I told him I might agree with him had he followed my recommendations.
Long story short, he paid when the account was turned over to a collection agency. It cost me 30% of the invoice, but it was worth it.
Best regards - Al
Update on the progress... I rejected the WPS, based on lack of PQR, and use of non specified tubing material... they then forwarded a PQR, tested last year, using API N-80 casing. The lab that tested it simply did a macroetch, and called it good. the report from the lab states "the welding was evaluated to AWS D1.1: 2006 Paragraph 4.8.4".., and also "the destructive testing was performed in accordance with ASME Section lX"... nothing like mix and match codes...
I don't have a spec. for this material. It's a 80ksi yield/100ksi min./110max. tensile, and I don't see it in D1.1 Table 3.1 (2006)
My boss signed off "no exceptions"on the WPS/PQR, and I told him I disagree. I would like to see welding/testing per AWS D1.1 4.11.3.
OVERRULED
I'm still gonna ding em for not using ASTM A500/B
work starts Monday.
Does anyone think that the PH/IP/PWHT temps are sufficient to join this material to ASTM A572 Gr. 50?
Just a quick question Duke, are you working as a third party inspector or are you employed by the EOR?
The reason I ask is because the TPI does not have the authority to override D1.1 or any other requirement of the project specification. Only the EOR, or the "Engineer" as D1.1 calls him, has that authority.
If your "boss" is not the “Engineer” he has no business circumventing the requirements of the project specification and if he is a SCWI or a CWI could be placing himself in a position where he could find himself before the Ethics Committee.
This places you into a sticky situation as well. The code of ethics places certain responsibilities on your shoulders. The EOR needs to be made aware of the nonconformance so he can make his determination whether the deviation is substantial or inconsequential. That is not your employer's call unless he is the EOR.
Neither you, as the TPI, or your employer, has the authority to accept WPSs. That responsibility lies with the EOR. He may ask for your recommendations, but it is his responsibility to say Yea or Nay on the WPSs, supporting PQR, etc. assuming the project specification references D1.1.
Best regards - Al
We are TPI on this project. Not to worry, my boss can do whatever he wants, I'm still going to write non conformance. Its a school project, DSA oversight, so even if they have RFI approval from EOR, it's NC unless DSA approved.
By Duke 
Date 09-29-2010 10:59
Edited 09-29-2010 11:07
Took a hard look at drawings sent over by the micropile SEOR; "tubing shall 'meet the tensile requirements of' ASTM A500 Grade B, with 15% minimum elongation..." it far exceeds it. No max on tensile in ASTM A500/B
