9.2 Clause 5 — Prequalification Requirements

9.2 Clause 5 — Prequalification Requirements

Clause 5 of AWS D1.1 defines the conditions under which a WPS can be used without procedure qualification testing (PQR). This is the prequalification concept — a major time and cost advantage unique to AWS D1.1.

Prequalification Conditions (ALL Must Be Met)

A WPS is prequalified only when all of the following conditions are satisfied:

1. Welding process — Only four are prequalified: SMAW, GMAW (except short-circuit transfer on CJP groove welds), FCAW, SAW
2. Base metal — Listed in Table 5.3 (approved base metals)
3. Filler metal — Matched per Table 5.4 (matching filler metals)
4. Joint design — Per prequalified details in Figures 5.1 (CJP) or 5.2 (PJP)
5. Preheat/interpass — Per Table 5.8 (minimum preheat temperatures)
6. All other Clause 5 requirements — Essential variables, technique, etc.

If any condition is not met, the WPS must be qualified by testing (PQR per Clause 6).

Table 5.3 — Approved Base Metals

Table 5.3 lists base metals approved for prequalified WPS, organized by:

• ASTM specification (e.g., A36, A572, A992)
• Grade/type (e.g., Gr 50, Gr 65)
• Steel group (for matching filler metals)
• Minimum preheat category (referenced in Table 5.8)

Common structural steels in Table 5.3:

• A36 — most common structural steel (Fy = 36 ksi)
• A572 Gr 50 — common HSLA steel (Fy = 50 ksi)
• A992 — standard for W-shapes (Fy = 50 ksi)
• A500 Gr B/C — HSS (round and rectangular tubing)
• A588 — weathering steel (Fy = 50 ksi)

Table 5.8 — Minimum Preheat and Interpass Temperature

This table specifies minimum preheat based on:

• Steel category (A, B, C, D — from Table 5.3)
• Thickness of the thickest part at the point of welding
• Welding process and hydrogen level (low-hydrogen vs. non-low-hydrogen)

Prequalified Joint Details (Figures 5.1 and 5.2)

Figures 5.1 (CJP) and 5.2 (PJP) provide detailed joint configurations including:

• Groove type (V, bevel, U, J, square)
• Groove angle ranges
• Root opening ranges
• Root face dimensions
• Permitted positions (all, flat/horizontal only)
• Process limitations
• Backing requirements (with/without)
• Weld thickness limits

Reading a prequalified joint detail: Each entry specifies the exact tolerances for joint preparation. If the actual joint preparation falls outside these tolerances, the joint is no longer prequalified and must be qualified by PQR.

Minimum Fillet Weld Size (Table 7.4)

While in Clause 7 (Fabrication), this table is frequently tested on Part C:

For the Exam: Part C questions often ask: "Is this WPS prequalified?" You must check all conditions in Clause 5 — process, base metal, filler metal, joint design, and preheat. If any condition is not met, the answer is "not prequalified — requires PQR per Clause 6."