Preliminary welding procedure specification
Preliminary welding procedure specification
(OP)
Dear all I hope you all fine
A little question ( could I weld thredolet or socket 3/4 inch with SMAW) for pwps
Thank you
A little question ( could I weld thredolet or socket 3/4 inch with SMAW) for pwps
Thank you





RE: Preliminary welding procedure specification
RE: Preliminary welding procedure specification
Thank you so much for responding
RE: Preliminary welding procedure specification
RE: Preliminary welding procedure specification
Best regards - Al
RE: Preliminary welding procedure specification
Sounds like more work than necessary and really a duplication of effort. You write a WPS and qualify it using a PQR.
RE: Preliminary welding procedure specification
You have the egg before the chicken.
You need the variables from the PQR to write the WPS.
As Al stated it is the engineers best guess to give to the welder to follow when welding the PQR coupon.
Predominantly used in ISO codes/standards.
It could be called a duplication of effort but it does have some beneficial uses.
As an example, we regularly get PWPS submitted by contractor to client (when working with ISO)for approval.
Waste of time and money qualifying a PQR if the client will not accept the final WPS (eg. may be code compliant but not project specification compliant)
Cheers,
Shane
RE: Preliminary welding procedure specification
The alternative is to throw a couple of plates on the bench and tell the welder, "Weld these." And hope for the best.
The code doesn't say the welding of the PQR needs to be witnessed, nor does ASME require nonessential variables be recorded. In my book it is a missed opportunity if the data isn't recorded. It explains why I get several phone calls every year asking, "I just qualified the WPS, but where do I get the values for the voltage, amperage, travel speed, for the WPS?"
Many years ago I did an audit on a large manufacturer that included reviewing their WPSs. I asked the engineer, "Who recorded these parameters on the PQR?"
"Our welder records that information while he welds the coupons." was the response.
"He must be a pretty good welder. Is there a chance I can meet him?" I asked.
"No problem, he's down on the production floor." says the engineer.
"Great, let's go say hello." I said with a smile.
Introductions all around, and I asked the welder, "Do you remember welding up the plates for this PQR?"
"Hell yea, that aluminum is a pain in the backside." Responds the welder.
"Did you record the voltage, amperage, and travel speed?" I asked.
"You don't know Jack about welding do you!" said the welder.
"What makes you say that? I said.
"If you knew anything about welding you would know darn well I can't watch the weld pool and the meters on the machine at the same time!" says the welder.
"Good point. Where could these values have come from if not from you and there was no one to witness you welding the plates?" I asked.
Now we have a PQR with falsified data. Scratch one PQR and one WPS. While we're at it, best check the other WPSs and supporting PQRs. Scratch one welding program, all their PQRs, all their WPSs and start over.
Best regards - Al
RE: Preliminary welding procedure specification
Thank you so much
RE: Preliminary welding procedure specification
I reject many more WPSs than I accept because the contractor simply meets Section IX without considering the construction code, PWHT, notch toughness, etc.
Just because the PQR and WPS was acceptable for a previous project, it doesn't mean it is acceptable for a new project that utilizes a different P number/group number, thickness, construction code, etc.
Best regards - Al
RE: Preliminary welding procedure specification
So in this case i'll accept the WPS and will proceed.
Thank you so much
RE: Preliminary welding procedure specification
Be very careful with trying to weld 3/4" with SMAW.
The thredolet/sockolet weld to run pipe must be a fully penetrated groove weld and you would need a highly skilled welder to do that without making a mess.
Much better option would be GTAW.
Cheers,
Shane
RE: Preliminary welding procedure specification
Best regards - Al
RE: Preliminary welding procedure specification
This is in arabic mean Allah bless you and guide you and me to his way
Thank you so much for your support.