Prequalified groove details · Clause 5
How do you select a prequalified CJP groove detail?
A CJP detail is a complete combination of groove geometry, process, position, thickness conditions, backing or backgouging construction and figure notes. Start with the target joint and select a matching Figure 5.1 row; a familiar groove shape alone does not establish prequalification.
Selection sequence
- Identify the joint family and members: butt, corner, T, or a combined configuration. Mark T1/T2/T3 on the sketch so each table condition has an unambiguous member.
- Choose the welding process and its suffix. A Figure 5.1 SMAW row is not interchangeable with a GF (GMAW/FCAW) or SAW row.
- Check the production position against that exact row. “All positions” is not implied by the CJP label.
- Check the listed thickness conditions and each groove dimension. Keep separate rows with different R/angle combinations separate.
- Determine the required backing construction or second-side preparation, then apply every lettered note printed for that row.
- Write the selected nominal dimensions, detail tolerances, fit-up tolerances, sequence and backing action into the WPS sketch and instructions.
Example: same single-V family, different process rows
| Figure 5.1 row (SI) | Listed process / detail | Position and construction | Selection implication |
|---|---|---|---|
| B-U2a, SMAW | T1=U; R=6 mm, α=45° | A; single steel backing; notes e, j | This exact geometry is the flat-position row. Separate SMAW rows list R=10 mm/30° and R=12 mm/20° for F/V/OH. |
| B-U2a-GF | GMAW/FCAW; separate combinations R=5 mm/30°, 10 mm/30° or 6 mm/45° | F/V/OH; single steel backing; notes a, j | These are process-specific rows. Do not substitute a SMAW row’s position or detail. |
| B-U2-GF | T1=U; R=0–3 mm, f=0–3 mm, α=60° | A; double-sided construction; note d requires backgouging to sound metal before welding the reverse side | This is a different open double-sided detail, not the single-V backed detail above. |
“U” in the table row is not permission to ignore every other limit. The exact material grouping, filler and process rules, position, thickness restrictions in linked tables, applicable notes, and project design still need review. The table rows above are examples of how the branch changes, not a recommendation for a particular project joint.
Keep detailed dimensions and fit-up limits distinct
Figure 5.1 provides both “As Detailed” and “As Fit-Up” tolerances. They serve different purposes. For example, the referenced backed SI profile permits R as detailed at +2/−0 mm and fit-up at +6/−2 mm, with its separately stated angle tolerances. Do not copy a tolerance profile from another detail family, system of units or row. A nominal zero root gap also cannot become a negative physical opening.
For mechanical/automatic GMAW, FCAW or SAW, the total root-gap variation along the joint is separately limited to 3 mm (1/8 in); greater variation requires local correction under the referenced provisions. Include actual fit-up controls and show the member orientation in the sketch.
Conditions that change the classification
- A single-sided non-tubular CJP detail requires steel backing unless the specific non-steel backing route is used: remove it after welding, backgouge to sound metal and weld the reverse side under 5.4.1.3.
- A double-sided groove without backgouging is generally treated as PJP for the Clause 5 rule; retain the specified 10.10.2 and Figure 5.1 B-L1-S exceptions rather than generalizing them.
- A single-sided joint with no backing is not CJP solely because the drawing or note says “full penetration.” Match an eligible Figure 5.1 detail or use the appropriate qualification route.
- A joint that needs dimensions outside the row, an unlisted process/position combination, or unsupported construction is not made prequalified by selecting the nearest-looking figure.
The companion backing and removal guide explains the decision boundary. For PJP, effective size is calculated from its own Figure 5.2 detail; see PJP detail selection.
Record enough detail for a usable WPS
Identify the selected figure/detail, unit system and code edition. Show members and thickness labels, root opening, root face, groove angle or angles, any radius, steel backing or spacer dimensions where applicable, side sequence, backgouging and reverse-side welding. State the applicable position, process, tolerances and figure notes. If the drawing or fabrication instruction does not provide a required design decision, keep that item unresolved instead of inventing a value.
Code basis and limits
Basis: AWS D1.1/D1.1M:2025 base edition plus the registered base-edition errata dated July 28, 2026; AMD1 is not included. Principal provisions: Clause 5.4.1 and Figure 5.1, including the applicable row dimensions and notes; related preparation and fabrication requirements apply as referenced. The contract edition governs a project.
The geometry summary here is not a structural design check and does not approve a weld detail. Confirm the complete controlled standard, design drawing, materials, process and project conditions before issuing a production WPS.
Provide the controlled drawing, governing edition, process, position and project constraints.