Welding procedure specification for GTAW & FCAW

Update ASME IX 2019
Deteled: QW-405.2

Scope of PQR

  • Material: API 5L Gr. X52N PLS2 SMLS
  • Pipe size: NPS 8” Sch 80 (12.7 mm)
  • Joint design: Groove, included angle 60 deg.
  • Welding process: weld metal deposit of GTAW (2.7 mm) and FCAW (10 mm).

Reference ASME II part A - base metals; part C - welding consumables, ASME B16.25 - end preparation.

Descriptions

Descriptions of WPS here.

QW-402 Joint details

Joint details of WPS shall be shown all variable in table QW-256 (for GTAW) and table QW-255 (for FCAW).

We should bring all variables in these tables and range of qualified application to new WPS.

  • QW-402.1 Groove design: as detailed in the PQR, eg. included angle: 60 +/-10 deg., Root gap: 3.2mm, Root face: <1mm, see ASME B16.25 – groove bevel ends.
  • QW-402.4 Backing: GTAW “N/A – not applicable”, FCAW “weld metal”.
  • QW-402.5 Backing: GTAW “None”; FCAW “N/A”.
  • QW-402.10 Root Spacing: 3.2mm
  • QW-402.11 Retainers: GTAW “None”; FCAW “-“.

QW-403 Base metal

Base metal of the test coupon as mentioned in the PQR, base metal qualification of WPS follow an assigned material in table QW-422 including of P number, group number, thickness qualification.

  • QW-403.5 Group no.: Gr-no. 1, see QW-422,
  • QW-403.6 T limits: 12.7 to 25.4mm,
  • QW-403.8 T Qualified: 5 to 25.4mm, see Table QW-451.1,
  • QW-403.9 t pass > 13mm: “None“,
  • QW-403.11 P Qualified: P-no. 1, see table QW-422,

Note: QW-402.5 and QW-402.6 shall apply when PQR required CVN test.

QW-404 Filler metal

  • QW-404.3 Size: GTAW: “2.4 mm”, FCAW: “n/a”;
  • QW-404.4 F Number: GTAW: “6”, FCAW: “6”; see table QW-432 and filler metal selection ASME II Part C SFA 5.18 Classification
    Note: we should use an electrode classification of ER70S-6 , due to more projects restricts a classification “G” and supplementary PQR required CVN test.
  • QW-404.5 A Number: GTAW: “1”, FCAW: “1”; see table QW-442,
  • QW-404.6 Diameter: GTAW: “n/a”; FCAW : “1.2mm”,
  • QW-404.7 Diameter > 6mm: GTAW: “n/a”; FCAW: “-“,
  • QW-404.12 Spec. or Class. A/SFA.: GTAW “A/SFA 5.18 ER70S-6”; FCAW “A/SFA 5.20 E70T-1C”,
  • QW-404.14 Filler: GTAW: “Yes”; FCAW: “n/a”,
  • QW-404.22 Consumable Insert : GTAW: “None”; FCAW : “n/a”,
  • QW-404.23 Filler metal product form: GTAW: “Solid” ; FCAW: “Flux cored”,
  • QW-404.24 Supplemental filler: GTAW: “n/a” ; FCAW: “None”,
  • QW-404.24 Alloy elements: GTAW: “n/a” ; FCAW: “None”,
  • QW-404.30 Max. Deposit thickness (t): GTAW: “6mm” ; FCAW : “19mm”, refer to table QW-451.1,
  • QW-404.32 t limits: GTAW: “n/a” ; FCAW : “None”,
  • QW-404.33 Classification: GTAW: “-“ ; FCAW : “-“, if not mentioned in the project specifications, please inorge this non-esstional variable,
  • QW-404.50 Flux : GTAW: “None” ; FCAW : “n/a”.

QW-405 Positions

ASME IX allows qualification either plate or pipe test coupon, and not restrict the position like AWS D1.1 except supplementary essential variables. These supplementary essential variables shall become an essential variable when addition of CVN test. If the PQR are not required the CVN test, the test coupon on plates also qualify for pipe and vice versa.

  • QW-405.1 + Position: “All”,
  • QW-405.3 change vertical welding: “-“,

Note :

The welder or welding operator who prepares the WPS qualification test coupons meeting the requirements of QW-200 is also qualified within the limits of the performance qualifications, listed in QW-304 for welders and in QW-305 for welding operators. He is qualified only within the limits for positions specified in QW-303.

QW-406 Preheat

Preheat temperature will effect to a quality of weldment such as high hardness value, impact test value at heat affected zone, etc.

  • QW-406.1 Decrease > 55 deg. C: “10 deg.C”,
    An atual preheat temperature recorded and then minus of 55 deg.C, refer to ASME B31.3 table 330.1.1 – preheat temperatures if the WPS application to ASME B31.3.
  • QW-406.2 Preheat maintenance: “-“,
  • QW-406.3 Increase > 55 deg. C: “250 deg. C”,
    Almost project specifications are allowed of interpass temperature max. 250 deg C.

QW-407 PWHT

  • QW-407.1 change PWHT: “None”
  • QW-407.2 change PWHT (T & T range): “-“
  • QW-407.4 T limits: “-“

QW-408 Gas

  • QW-408.1 Trailing or composition: GTAW: “SG-A”, FCAW: “SG-C”, see AWS A5.32,
  • QW-408.2 Single, mixture %: GTAW: “99.997%”, FCAW: “100%”, refer to AWS A5.32,
  • QW-408.3 Flow rate: GTAW: “10-15 lpm”, FCAW: “10-17 lpm”,
  • QW-408.5 Backing flow: GTAW: “None”, FCAW: “-”,
  • QW-408.9 Backing or composition: GTAW: “None”, FCAW: “-”,
  • QW-408.10 Shielding or trailing: GTAW: “-”, FCAW: “-”,

QW-409 Electrical characteristics

  • QW-409.1 Heat input: calculation HI = (V x A x 60)/ TS (travel speel – mm/minute). Running PQR should control HI value between 1.0 to 3.5 kJ,
  • QW-409.2 Transfer Mode: GTAW: “n/a”, FCAW: “None”,
  • QW-409.3 Pulsing current: GTAW: “None”, FCAW: “n/a”,
  • QW-409.4 Current and Polarity: GTAW: “DC EN”; FCAW: “DC EP”
  • QW-409.8 I & E range: GTAW “A: 80 – 150”, “V: 10-14”; FCAW “A: 100-200, V:20-30”.
  • QW-409.12: Tungsten electrode: GTAW: “2.4mm, 2%thoriated”, FCAW “n/a”,

QW-410 Technique

  • QW-410.1 String/weave: GTAW: “string/weave”, FCAW: “string/weave”,
  • QW-410.3 Orifice, nozzle or gas cup size: size no.: GTAW: “4 – 7”, FCAW: “3/4”,
  • QW-410.5 Method cleaning: “grinding, wire brushing”,
  • QW-410.6 Method back gouge: “None”,
  • QW-410.7 Oscillation: “None”, due to manual/ semiauto process,
  • QW-410.9 Multi to single pass/ side: “Multi”,
  • QW-410.10 Single to multi electrodes: “Single”,
  • QW-410.11 Closed to out chamber: “None”,
  • QW-410.15 Electrode spacing: “None”,
  • QW-410.25 Manual or automatic: Manual “GTAW” & Semiauto “FCAW”,
  • QW-410.26 Peening : “None”,
  • QW-410.64 Use of thermal processes: “None”,

Conclusion

The WPS(s) can aid in preparing your PQRs, minimizing your costs to get qualified on a new material, and save time.

8 Likes

Do we combine 2 PQRs in a welding procedure?

PQR 1 is GTAW - range 1.5 - 11.08 mm (6G - qualified on pipe, P1)
PQR 2 is FCAW with backing - range 5 to 25.4 mm (3G - qualified on plate, P1)

Please advise range of qualification.

Thanks in advance

Can I use this WPS with full GTAW on pipe 2" 3.91 WT?

Your mean above question is

  • PQR 1:deposit of GTAW 5.54 mm
  • PQR 2: deposit of FCAW 12.7 mm

In my opinion, 2 PQRs can combine in a WPS or can use in a joint. Max. thickness base metal and max deposited weld metal thickness are determined in accordance with QW-451.

2 Likes

Many thanks,
Should I input range of base metal qualification in this WPS?

I think this WPS is not allowed to weld thickness range less than 5 mm.
Even thickness of test coupon equal to 12.7 mm and meed QW-200.4 b).
It also is not met QW-200.4 a) 2) and table QW-451

Other comments, please advise him!

2 Likes

Trailing definitions?
How to identify in WPS?

Traling gas updated in new edition of ASME IX 2017.

QW-109.2 Traling gas states
" a gas used to produce a protective atrmoshere that extends beyond the weld pool in the direction opposite of travel


(huntingdonfusion photo)

See topic Weld Trailing Shield of TIG (GTAW) or Plasma (PAW) welding torch or TAG Trailing Shields


(Gaswork photo)

2 Likes

This definition in new 2017 edition.

1 Like