Prequalified WPS — What D1.1:2025 Allows
A DMOS préqualifié meets all Exigences of D1.1:2025 Clause 5 without requiring a Qualification de Mode Opératoire de Soudage (PQR). Prequalification covers four processes — SMAW (Tableau 5.1), SAW (Table 5.2), GMAW solid wire (Table 5.3), and FCAW/GMAW metal core (Table 5.4) — when all essential variables stay within Code-defined Limites.
What Makes a WPS Préqualifié?
Under D1.1:2025 Clause 5, a WPS is prequalified when every Variable essentielle — process, Groupe de métal de base, Métal d'Apport, Détail du joint, position, Préchauffage, and Température entre Passes — falls within the limits specified in the relevant code tables. Process limits are in Tables 5.1–5.4, essential variables in Table 5.5, base metals in Table 5.6, filler metals and shielding gases in Tables 5.7–5.10, and preheat and interpass temperatures in Table 5.11. When all variables meet the code requirements, no Essai de qualification (PQR) is required before production Soudage begins.
Prequalified status is process-specific. Table 5.1 covers SMAW, Table 5.2 covers SAW, Table 5.3 covers GMAW (solid wire only — GMAW-S is not prequalifiable), and Table 5.4 covers both FCAW and GMAW metal core together. Each table specifies the allowable parameter ranges for that process.
Prequalified Métal de Base Groups
Table 5.6 lists the base metals approved for prequalified WPSs. The 2025 edition added a new Group V consisting of ASTM A913 Grade 80 — the only material in this high-Résistance Catégorie. Groups I through IV cover the common structural steels: A36, A572, A992, A913 Gr50/65/70, and others. Base metals not listed in Table 5.6 require a qualified WPS with PQR Essai under Clause 6.
Preheat Requirements for Prequalified WPSs
Minimum preheat and interpass temperatures for prequalified WPSs are established by Table 5.11 (see Clause 5.7), which lists requirements by steel Spécification, process category (A through G), and material Épaisseur. The 2025 edition added three new categories: Category E (A1066 Gr.50/60/65 with H8 electrodes), Category F (A913 Gr.70 with H8 electrodes), and Category G (A913 Gr.80 with H4 electrodes). Categories A through D cover the common structural and higher-strength steels with conventional and Bas Hydrogène processes. Preheat values in Table 5.11 are mandatory minimums — the WPS must specify a Température de Préchauffage at or above the table value for the given material and thickness.
When Prequalification Does Not Apply
Electroslag welding (ESW) and electrogas welding (EGW) are not prequalifiable — they require qualification testing under Clause 6. Joints not shown in the prequalified joint details of Clause 5.4 must also be qualified. If any essential variable falls outside the Table 5.1–5.4 limits, the WPS requires a PQR. See the PQR guide for D1.1's two qualification paths.
Common Prequalification Mistakes
Fabricators frequently encounter prequalification failures from variables that appear minor but violate Clause 5 limits. GMAW short-circuit transfer (GMAW-S) is not prequalifiable under any condition — Clause 5.5.1 requires the mode of transfer to not be short circuit for GMAW prequalification. Using GMAW-S requires qualification under Clause 6 with PQR testing regardless of base metal or joint type.
Exceeding Table 5.1–5.4 parameter limits is another common issue. Each process table specifies Maximum Diamètre d'électrode, maximum single-pass filler metal Taille, maximum welding current ranges, and layer thickness limits. For example, Table 5.1 (SMAW) limits the maximum Électrode diameter to 1/4 in [6.4 mm] for flat-position groove welds and 3/16 in [4.8 mm] for all other positions. Passe de fond electrodes are further restricted to 3/16 in [4.8 mm] maximum. A WPS that specifies an electrode diameter or current outside these ranges cannot claim prequalified status.
Non-prequalified joint details also require qualification testing. Clause 5.4 provides specific joint geometries — groove angles, root openings, Talon dimensions, and Support envers requirements — for CJP and PJP groove welds and fillet welds. Any joint configuration not matching the prequalified details in Clause 5.4 figures requires a qualified WPS under Clause 6, even if all other variables (process, base metal, filler metal) are within prequalified limits. Modifying a prequalified joint detail — such as reducing the Angle d'ouverture below the listed Minimum — invalidates the prequalification.
Full content coming. This page is being expanded with complete Tables 5.1–5.4 parameter ranges, a prequalification Liste de Contrôle, and worked examples. Use the preheat calculator for Table 5.11 lookups in the meantime.
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Frequently Asked Questions
A WPS is prequalified when every essential variable — process, base metal group, filler metal, joint detail, position, preheat, and interpass temperature — falls within the limits specified in D1.1:2025 Clause 5. Process limits are in Tables 5.1–5.4, base metals in Table 5.6, filler metals in Tables 5.7–5.10, and preheat in Table 5.11. No PQR testing is required.
Four processes are prequalifiable: SMAW (Table 5.1), SAW (Table 5.2), GMAW with solid wire only (Table 5.3), and FCAW/GMAW metal core combined (Table 5.4). GMAW short-circuit transfer (GMAW-S) is not prequalifiable. Electroslag welding (ESW) and electrogas welding (EGW) require qualification testing under Clause 6.
Table 5.6 lists approved base metals in Groups I through V. Groups I–IV cover common structural steels including A36, A572, A992, and A913 Gr50/65/70. The 2025 edition added Group V for ASTM A913 Grade 80. Base metals not listed in Table 5.6 require a qualified WPS with PQR testing under Clause 6.
Prequalification does not apply when any essential variable falls outside the Table 5.1–5.4 limits, when the joint is not shown in the prequalified joint details of Clause 5.4, or when using ESW or EGW processes. GMAW short-circuit transfer (GMAW-S) is also excluded from prequalification per Clause 5.5.1, even though standard GMAW spray transfer is prequalified. In all these cases, the WPS must be qualified with a PQR under Clause 6.
A prequalified WPS can fail inspection for several reasons even though no PQR testing was required. The most common failures are: exceeding the essential variable limits of Table 5.5 during production welding (for example, welding outside the documented amperage range or exceeding the maximum interpass temperature), using a joint detail that does not match the prequalified joints in Clause 5.4 and Figure 5.1, failing to meet the minimum preheat requirements of Table 5.11, or producing welds that do not meet the visual acceptance criteria of Table 8.1. Prequalified status means the procedure is approved without testing — it does not exempt the production welds from meeting all quality requirements of Clauses 7 and 8.
No. Under D1.1:2025 Clause 5, a prequalified WPS is exempt from the qualification testing required by Clause 6. This means no test coupon, no destructive testing, and no procedure qualification record. The code has already validated the joint configurations, processes, and parameter ranges covered by Clause 5. However, the welder must still be qualified per Clause 6 Part C — prequalification of the procedure does not extend to the welder. If any variable on your WPS falls outside the prequalified limits, the exemption does not apply and you must qualify the WPS with PQR testing per Clause 6.2.1.