clause5.io/ Welding/ WPS Template

The 21 Essential Variables (Table 5.5)

D1.1:2025 Table 5.5 lists the variables that must appear on every 事前認定WPS. The upper section (items 1–21) defines what must be included; the lower section (items 22–31) defines permitted tolerances. When any variable is changed beyond its permitted tolerance, a new or revised WPS is required per 条項 5.2.1.

Variables listed thematically. For the official numbered order, see D1.1:2025 Table 5.5 items (1)–(21).

Common WPS Mistakes That Fail Inspection

Inspectors reviewing WPSs on the shop floor see the same errors repeatedly. Avoiding these is the difference between a smooth audit and a corrective action report.

Missing or incomplete essential variables. The most common failure is simply leaving fields blank. Every one of the 21 variables in Table 5.5 must have a value or range documented. A WPS with "TBD" or blank 電流 ranges is not a valid 文書WPS per Clause 5.2.1. Inspectors will reject it on sight.

Preheat below 最小. The WPS must list a minimum 予熱温度 that meets or exceeds the Table 5.11 requirement for the 母材群, process, and 板厚. Fabricators sometimes list "N/A" for 予熱 when the code actually requires a minimum — particularly for Group II and Group III steels above certain thicknesses. Use the preheat calculator to 確認.

Filler metal mismatch. Table 5.7 defines which filler metal classifications match each 母材 group. A WPS listing E7018 for Group IV steel (which may require E8018 or higher matching) will fail verification. The 溶加材分類 on the WPS must match the 要求事項 for the specific base metal group and process.

Joint detail not 事前認定. Fabricators sometimes specify groove angles, root openings, or バッキング conditions that do not match any prequalified joint detail in Figures 5.1, 5.2, or 5.3. If the joint is not prequalified, the WPS must be qualified per Clause 6 with a PQR — the prequalified path does not apply.

Parameter ranges too wide. Writing "amperage: 50-400A" to cover every possible scenario defeats the purpose of the WPS. Inspectors expect reasonable ranges that reflect actual 溶接 practice for the specified 電極径 and position. Excessively wide ranges suggest the WPS was written to avoid revision rather than to control the process.

WPS not signed or dated. The WPS must bear the signature (or authorized signature equivalent) of the 製作者’s designated representative. An unsigned WPS is not an approved document. Some 検査 agencies also require a revision number and date to track document control.

How to Fill Out a WPS Form

Step 1 — Identify your base metal. Find the ASTM specification on your mill test report. Look it up in D1.1 Table 5.6 to find the base metal group (I through V). This determines your preheat カテゴリー and filler metal matching requirements.

Step 2 — Determine preheat. Use your base metal group with your 溶接工程 and material thickness to look up the minimum preheat and パス間温度 in Table 5.11. The preheat calculator does this lookup instantly.

Step 3 — Select the joint detail. Choose the applicable prequalified joint detail from Figures 5.1 (CJP groove welds), 5.2 (PJP groove welds), or 5.3 (fillet welds). The figure specifies ルート間隙, 開先角度, backing requirements, and 溶接サイズ. See the prequalified WPS reference for the full set.

Step 4 — Match filler metal. Table 5.7 defines the matching 強度 filler metal for each base metal group and welding process. The filler metal classification on your WPS must match.

Step 5 — Document electrical parameters. Record amperage, 電圧, and 溶接速度 ranges for each 電極 diameter and pass type. These must stay within the ranges on the WPS during production welding — deviations require a new WPS.

WPS Document Control Best Practices

A WPS is a controlled document. In AISC-certified shops, the WPS program is reviewed during the annual audit. In ASME Code shops, the Quality Assurance Manual references WPS control procedures. Good practices include:

Unique identification. Each WPS should have a unique number (e.g., WPS-001, WPS-002) that is referenced on the 溶接士’s 資格記録 and on the 溶接 map or drawing. This creates traceability from the finished weld back to the procedure used to make it.

Revision tracking. When a WPS is revised — to add a new electrode diameter, change a parameter range, or update a preheat value — the revision should be documented (Rev A, Rev B, or Rev 1, Rev 2). The previous revision should be archived, not deleted, so the inspection record shows which version was used for each weld.

Shop floor accessibility. The current WPS must be available at the point of welding. Whether printed and posted at the workstation, available on a tablet, or accessible through a shop management system, the welder must be able to reference the WPS while welding. A WPS locked in the QC office serves no purpose.

Supporting PQR linkage. For qualified (non-prequalified) WPSs, the supporting PQR number should be referenced on the WPS. This allows an 検査員 to quickly verify that the procedure has been tested. For prequalified D1.1 WPSs, no PQR reference is needed — but the WPS must explicitly state it is prequalified per Clause 5.

WPS Form Sources

AWS Annex J (D1.1:2025 page 407) provides sample WPS and PQR forms. These are informative — not mandatory. They serve as a starting point for fabricators who do not have their own standardized forms.

AWS Annex K (D1.1:2025 page 429) provides a reference チェックリスト of all code subclauses that a prequalified WPS must address, organized by clause. Use it as a verification tool after completing the WPS to ensure nothing is missed.

Most AISC-certified 製作 shops, bridge fabricators, and inspection training programs use their own standardized WPS forms. The format does not matter — only the content. Per Clause 5.2.1, the WPS must be a written document that addresses all applicable variables. Need help filling it in? See our field-by-field WPS form guide.

Multi-規格 WPS 比較: D1.1 vs. ASME IX vs. API 1104

Every fabrication code requires a written WPS, but the rules differ significantly in scope, qualification path, and 重要変数 definitions. Understanding these differences is critical when a project crosses code boundaries — for example, a structural support (D1.1) welded to a pressure vessel nozzle (ASME IX), or a pipeline tie-in (API 1104) meeting a structural connection.

Qualification Path

D1.1 offers two paths: prequalified (Clause 5, no 試験 required) and qualified (Clause 6, PQR required). If SMAW, SAW, GMAW, or FCAW is used on Table 5.6 steels with Clause 5 joint details, no PQR is needed. This prequalified path exists only in D1.1 — no other major code allows it.

ASME IX requires 手順資格 (PQR with 破壊試験) for every WPS. There is no prequalified path. Each WPS must reference a supporting PQR that demonstrates the procedure produces acceptable results. The PQR records actual test parameters and mechanical test results (tension, guided bend, impact when required). Standard 溶接施工法 Specifications (SWPSs) published by AWS may be adopted per QW-500 as an alternative, but the organization must accept responsibility for their use.

API 1104 also requires procedure qualification for every WPS per Section 5. The welder welds a 試験片 under the WPS conditions, and the coupon is destructively tested (nick break, tensile, bend, macro). There is no prequalified path, and the testing requirements are specifically designed for pipeline girth welds — including requirements for 放射線透過試験 of the qualification coupon.

Essential Variables Comparison

ASME IX WPS Essentials

ASME IX organizes essential variables by welding process in Tables QW-252 through QW-265. Each table lists the variables that apply to a specific process (SMAW, SAW, GMAW, GTAW, etc.) and classifies them as essential, supplementary essential (when impact testing is required), or nonessential. A change in an essential variable requires requalification of the WPS — meaning a new PQR with fresh test coupons.

The base metal grouping system is fundamentally different from D1.1. Instead of five groups based on preheat category, ASME IX assigns every material specification a P-Number and Group Number in Table QW/QB-422. A WPS qualified on one P-Number material generally covers all materials within that same P-Number, with some exceptions for Group Number changes in impact-tested applications. This system covers over 2,000 material specifications across ferrous alloys, stainless steels, nickel alloys, aluminum, copper, titanium, and zirconium.

Filler metals are classified by F-Number (usability grouping, Table QW-432) and A-Number (溶接金属 chemistry, Table QW-442). A change in F-Number is always essential. A change in A-Number is essential for certain processes and when impact testing is required.

API 1104 WPS Essentials

API 1104 governs welding of pipelines and related facilities. Its WPS requirements in Section 5 are specifically designed for girth welds on pipe — typically single-V groove joints welded in fixed position. The essential variables include process type, base metal (grouped by specified minimum yield strength), wall 厚さ範囲, 継手設計, filler metal group, electrical characteristics (AC/DC, 極性), position, direction of welding (uphill or downhill for vertical joints), シールドガス composition and flow rate, preheat, and interpass 温度 限界値.

A distinguishing feature of API 1104 is the 資格試験 requirements: test coupons are subjected to tensile, nick break, and guided bend tests. 放射線透過 examination of the 試験溶接 is also commonly performed. The standard allows qualification on a range of wall thicknesses and pipe diameters — the qualified range depends on the test coupon dimensions.

Unlike D1.1 and ASME IX, API 1104 treats the direction of welding (uphill vs. downhill) as an essential variable. Changing from downhill ルートパス to uphill root pass, or vice versa, requires requalification. This is critical for pipeline productivity — downhill welding is faster but requires different techniques and parameters.

Choosing the Right Code for Your WPS

Structural steel fabrication (buildings, bridges, industrial structures): Use D1.1. The prequalified path eliminates qualification testing costs for common joints on common steels — the most efficient path when the fabricator is using standard processes on Table 5.6 materials.

Pressure vessels and boilers (ASME Boiler and Pressure Vessel Code): Use ASME IX. All WPSs require PQR backing. The P-Number system provides the most comprehensive material classification of any 溶接コード. Required for ASME Code-stamped equipment.

Pipelines and piping systems (cross-country pipelines, gathering lines, facilities): Use API 1104. The qualification testing and essential variables are optimized for the specific challenges of field パイプライン溶接 — fixed position, varying wall thickness, uphill/downhill progression.

Crossover situations: When a project requires 適合 with multiple codes (e.g., pipe rack structural members under D1.1 supporting a piping system under ASME B31.3 referencing ASME IX), each code’s WPS requirements must be met independently. A WPS qualified under ASME IX cannot be used for D1.1 work unless it also meets the D1.1 prequalification rules or has been separately qualified per Clause 6.

"The WPS form is just a container. What matters is that every essential variable from Table 5.5 is documented, traceable, and followed on the shop floor."

— Standard fabrication guidance, consistent with D1.1:2025 Clause 5.2.1

Reference data from AWS D1.1/D1.1M:2025, ASME BPVC IX:2025, and API 1104. Not affiliated with AWS or ASME.