Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Used shielding gas PQR

Status
Not open for further replies.

1973Patrick

Petroleum
Aug 6, 2012
14
Hello,
I have a PQR:
Code AWS D1.1
Process: GMAW
Material: S235JR
Filler: Lincoln LNM 26 ER70S-6. AWS A5.18
Prescribed shielding gas: Ar or Ar-CO2

Gas used for PQR:
Shielding gas: (M24 - Ar-CO2-O2)

I think this is not allowed because:
Applied shielding is not in accordance with supplier data sheet
Applied gas is not in accordance with AWS A5.18

Is my opinion correct or is this allowed in accordance with AWS D1.1?

Rg Patrick
 
Replies continue below

Recommended for you

1973Patrick,
Did you mean "I have a WPS" ?
Have a look at Table 4.5 (19)
Cheers,
DD
 
Hi DekDee,
yes I have, butt the used gas inthe PQR was Ar-C02-O2)
I think oxygen is not allowed (O2 not approved). See attachement filler matwerial from supplier.
Patrick
 
Patrick, not allowed by who? Ar/Co2/O2 IS listed in AWS SFA 5-32. You have a Procedure and the full suite of tests and NDT etc prescribed by D1.1.
Don't try working to EN standards when using American standards.
 
rodofgod,

the supplier has determined the mechanical properties as welded with C0[sub]2[/sub]-Ar and not with O[sub]2[/sub].
I think this is not correct.
 
The purpose of qualifying a WPS by testing, i.e., welding a test assembly and performing NDE and destructive tests, is to demonstrate the proposed WPS will produce the required mechanical properties. The purpose of the PQR is record exactly what was done to demonstrate the WPS is viable.

If one wants to store the welding electrode under water before using them (no, I am not saying that it is a good idea), one must demonstrate that doing so will not be detrimental to the outcome. Welding a test assembly using the electrodes stored under water is allowed if it can be demonstrated the electrodes are still capable of producing a weld that has the required tensile strength, soundness, and any additional properties dictated by the applicable welding standard. The other/additional properties may include the ability to meet visual acceptance criteria, radiographic acceptance criteria, hardness requirements, notch toughness, and chemistry. That said, providing all the test results are acceptable, the electrodes stored under water would be permitted for production welding.

In your case, any shielding gas or mixtures of gases that was used to weld a test assembly that produces acceptable results can be used for production.

Best regards - Al
 
Patrick,as Al and myself have tried to assure you, as long as you have an accepted proven PQR/WPS structure in place using the M24 or rightfully (under AWS!) SG-ACO 12/2,designated shielding gas, you will be within the auspices of AWS D1.1. BTW, the data sheet or the welding consumable must be very old. Nearly,if not all those EN standards have been superseded by different ones.Not an unusual situation with Euro Norms.
 
Guys,
Is the deletion of the O2 not an essential variable ?

19) A change in shielding gas from a single gas to
any other single gas or mixture of gas, or in
the specified nominal percentage composition
of a gas mixture, or to no gas

Cheers,
DD
 
DekDee, nothing has been deleted! If the original PQR was performed with this tri mix gas (SG-ACO 12/2 or M24) then how can the continued use of same shielding gas be a problem for production welds given the PQR passed and welders have passed WPQ's using WPS's written from the original PQR?
 
I must be missing something. Where or when was it said that the WPS was revised and a different gas used for production? Color me confused!

Was the gas used for production the same as the gas used to qualify the WPS?

As long as the nominal percentages of the various components of the gas mix recorded by the original PQR are the same as that used for production, all is good. If the composition of the gas is subsequently changed, then a revised WPS is required and it must be qualified by testing with the parameters used recorded (while welding the test assembly) with the test results on a new PQR.

By the way, "Hello DekDee" aka Shane. How's life treating you?



Best regards - Al
 
ROG,
Hello,
I have a PQR:
Code AWS D1.1
Process: GMAW
Material: S235JR
Filler: Lincoln LNM 26 ER70S-6. AWS A5.18
Prescribed shielding gas: Ar or Ar-CO2

Gas used for PQR:
Shielding gas: (M24 - Ar-CO2-O2)

When I saw "Prescribed Shielding Gas: Ar or Ar-CO2" I presumed he actually meant to say "I have a WPS" and not PQR as stated.
Then it states the gas used for the PQR was Ar-CO2-O2 - hence the reference to the deletion of the O2 from PQR to WPS.

Hi Al,
Just got back to Malaysia this morning from a great week of R&R home in Thailand.
Flew back on Malaysia airlines - quite happy to get feet on the ground after what has happened.
How is life treating you - all good ?
 
All is good. Spring is around the corner. The snow, well, let's just say we had sufficient amounts of snow to satisfy our needs for one season.

I just finished a three week road trip for AWS and ASME, so it nice to be home for a bit. I should be in New Jersey for a small job this week. Day trips are a nice change.

The grandsons are wrapping up their hockey season and are going into spring training to prepare for next season.

All is good.

Do you have my E-mail. If not, check the other site so we can keep in touch.



Best regards - Al
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor