AWS D1.1 interpretation

Date 08-30-2003 09:55

Scope:
1. AWS D1.1: 2000 Table 4.5 addresses the PQR essential variable changes requiring WPS re-qualification for SMAW, SAW, GMAW, FCAW, & GTAW. Clause 4.7.1 states that changes beyond the limitations of PQR essential variables shown in Table 4.5 shall require re-qualification of the WPS.
2. Table 4.5 S.No. 32 states that “a change in groove type (e.g., single-V to Double-V). Qualification of any CJP groove weld qualifies for any groove detail complying with the requirements of 3.12 or 3.13)” as an essential variable. Table 4.5 S.No. 33 states that “a change in type of groove to a square groove and vice versa” is an essential variable.
3. Table 4.5 S.No. 32 states that “For the PQR groove area, an increase or decrease >25% in the number of passes” is an essential variable. Note 6 mentions that “If the production weld groove area differs from that of the PQR groove area, it is permissible to change the number of PQR passes in proportion to the area without requiring re-qualification”.
Purpose of enquiry:
Interpretation of the code requirement for the following cases.
1. There are two PQRs, one qualified with SMAW for 6G position, on an 8in. sch.80 pipe (as per table 4.2), and another qualified with FCAW for 6G position, on an 8in. sch.80 pipe (as per table 4.2).
2. There are two PQRs, one qualified with SMAW for 6GR position, on a test joint (as per Figure 4.27), and another qualified with FCAW for 6G position, on a 6 in. sch.120 pipe (as per table 4.2).
3. A PQR has been qualified with SMAW process on an 8 in. Sch.80 pipe using a single- V CJP as per Figure 4.24. For e.g. let the PQR have a groove area of 75mm2 and 25 passes with SMAW process.
4. A PQR has been qualified with SMAW process on an 8 in. Sch.80 pipe using a single- V CJP as per Figure 4.24.

Proposed reply:
1. Can the two PQRs be combined to make a WPS with SMAW root and hot pass and the remaining welding with FCAW such that the essential variables for both the SMAW and FCAW processes as per table 4.5 are maintained.
2. Can the two PQRs be combined to make a WPS with SMAW root and hot pass and the remaining welding with FCAW for a T-,K- Y-production joint such that the essential variables for both the SMAW and FCAW processes as per table 4.5 are maintained.

3.
a. Can the PQR be used to make a WPS for welding a Production single- V CJP joint for an 8in. Sch 80 pipe with 75mm2 area such that the number of passes is 32 such that all the other essential variables for the SMAW process as per table 4.5 is maintained.?
b. Can the PQR be used to make a WPS for welding a Production double- V CJP joint for a 50 mm thickness pipe such that the number of passes is 545 for a 1310 mm2 weld groove area such that all the other essential variables for the SMAW process as per table 4.5 is maintained.?
c. Can the PQR be used to make a WPS for welding a Production double-V CJP joint for a 50 mm thickness pipe such that the number of passes is 560 for a 1310 mm2 weld groove area such that all the other essential variables for the SMAW process as per table 4.5 is maintained.?
d. Can the PQR be used to make a WPS for welding a Production double bevel CJP joint for a 50 mm thickness pipe such that the number of passes is 272 for a 655 mm2 weld groove area such that all the other essential variables for the SMAW process as per table 4.5 is maintained.?
4.
a. Can the PQR be used to make a WPS for a production fillet weld with a single pass of maximum 6mm such that all the other essential variables for the SMAW process as per table 4.5 is maintained.?
b. Can the PQR be used to make a WPS for a production fillet weld with multiple pass of 8mm and over such that all the other essential variables for the SMAW process as per table 4.5 is maintained.?

By pipewelder_1999 (****)

Date 08-31-2003 13:56

Sayee,
This is the same as my post on eng-tips ( http://www.eng-tips.com/viewthread.cfm?SQID=69352&SPID=178&page=1 )but I figured I would post it here to allow others that to review and correct as needed.

I'll take a stab at it,

1)Yes (Revised from the eng-tips pos)
2) Yes, provided the 6gr coupon was 6" diameter else the minimum diameter would be restricted. Fig 4.27 only lists a minimum diameter.

3) a) No. You could increase the number of passes by up to 25% for the PQR Groove area. 32 is an increase greater than 25%

b) In the test setup you had .33 passes per mm^2 . You could increase that by 25% per note 5 up to .412 Passes per mm^2. The increase you note above is .416 passes per mm^2 which is above the allowable increase of up to 25%. NO

c) Same as above. The increase is greater than 25%. NO
d) Same as above . The increase is greater than 25%. NO

4) I'm still studying this

Anyway, thats what I could discover. I hope that you will correct me or advise me of any of the areas whare I may be off. My math stopped in the 9th grade so I may have made an error regarding the cross sectional area but I think its correct.

Gerald Austin
Iuka, Mississippi
http://www.weldinginspectionsvcs.com

By MBSims

Date 08-31-2003 16:15

Doesn't this question highlight how ridiculously confusing D1.1 has become? There is no apparent logic to back up the tolerances or ranges they apply to variables, especially for welder qualifications. That's why my company uses D1.1 as little as possible.

Marty

By pipewelder_1999 (****)

Date 08-31-2003 18:08

It's odd too. Many think ASME Sec IX is to be stayed away from and they should stay with D1.1. I would much rather perform qualifications both welders and procedures to SEC IX.

GA

By sayeeprasad (*)

Date 09-01-2003 11:19

Gerald
As you can see from the format, it is in line with Appendix F requirements for Technical Queries on AWS D1.1. I have sent this query to AWS and will post their reply as soon as I have one. Meanwhile, there are advantages to using either of AWS D1.1 or ASME section IX for welder and procedure qualifications. ASME Sec IX has listed only P Nos materials which are used for fabrication of pressure vessels boilers piping etc. Whereas AWS D1.1 lists materials used for Structurals. On Filler metals for e.g., AWS D1.1 is more lenient than Sec IX. Section IX does not talk about multiple wires/arc for SAW w.r.t weldeer quals.....
At the outset, I would not think of using Sec IX as the basis for all welder or procedure qualifications, but I do agree that AWS D1.1 is not as clear as ASME sec IX requiremsnts are. But that makes me happy as it justifies the existence of professionals like us;-) Meanwhile, your understanding is the same as mine.

By pipewelder_1999 (****)

Date 09-01-2003 13:09

I do agree that they both have there place but I have a much easier time interpreting ASME requirements. I DO think that there should be prequalified procedures for ASME work that DO not have to be purchased.

You do have a point about justification but just think how many small fabricators just "give up" in trying to work too a code because of the difficulty in working with it.

A book should not require another book on how to understand it.

Have a good day
G Austin

Gerald Austin