{"id":4153,"date":"2026-05-19T02:05:39","date_gmt":"2026-05-19T02:05:39","guid":{"rendered":"https:\/\/zxweldingrobot.com\/?p=4153"},"modified":"2026-05-19T02:05:39","modified_gmt":"2026-05-19T02:05:39","slug":"welding-procedure-specification","status":"publish","type":"post","link":"https:\/\/zxweldingrobot.com\/es\/blog\/welding-procedure-specification\/","title":{"rendered":"Welding Procedure Specification: Complete WPS Guide [2026]"},"content":{"rendered":"
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A welding procedure specification is the backbone of your welding operation, controlling how every qualified weld is made – the procedure, materials, parameters, and tests used to turn an as-delivered joint into a code-conforming weld. A weld procedure specification that is not written and qualified correctly is an insurmountable barrier to re-assurance from any inspector, contractor, or auditor that a weld will perform adequately in-service.<\/p>\n

In this guide we will walk through the full WPS lifecycle: what a welding procedure specification contains, how it differs from a Procedure Qualification Record (PQR), which code specification applies to your work, and how robotic welding makes WPS documents even more important – not less. Whether you are writing your first section IX compliant WPS or reviewing a world class AWS D1.1:2025 prequalified WPS, this guide covers it all.<\/p>\n

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WPS Quick Reference<\/h3>\n\n\n\n\n\n\n\n\n
Document Type<\/td>\nFormal written welding standard (instruction document)<\/td>\n<\/tr>\n
Governing Bodies<\/td>\nASME Section IX, AWS D1.1:2025, ISO 15614-1, API 1104<\/td>\n<\/tr>\n
8 Essential Sections<\/td>\nJoint, base metal, filler, preheat, electrical parameters, position, PWHT, testing<\/td>\n<\/tr>\n
Supported Processes<\/td>\nSMAW, GMAW, FCAW, GTAW, SAW, PAW, and hybrid combinations<\/td>\n<\/tr>\n
Qualification Path<\/td>\npWPS \u2192 test coupon \u2192 PQR \u2192 certified WPS<\/td>\n<\/tr>\n
Validity<\/td>\nValid until an essential variable changes beyond qualified range<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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What Is a Welding Procedure Specification (WPS)?<\/h2>\n

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A welding procedure specification sets out repeatable parameters for how an individual weld must be made in order to ensure quality. If you think of it as a recipe, then a WPS specifies the recipe for fabricating a joint: it defines in detail the process which can be used, what base metals and filler metals are allowed, at what settings to operate, in which directions the weld can be made, and what tests are required afterwards to prove the weld is defect free.<\/p>\n

The American Welding Society standard AWS B2.1\/B2.1M:2021<\/a> defines a WPS as “a written document that provides direction to the welder or welding operator for making production welds in accordance with Code requirements.” Bear in mind the caveat “in accordance with Code requirements” \u2014 a WPS is not a suggestion. Under the ASME Boiler and Pressure Vessel Code, AWS D1.1 Structural Welding Code, and ISO 15614 internationally, a WPS is a mandatory pre-condition for certified production welding.<\/p>\n

Why does this documentation matter at scale? The Welding Institute (TWI) conducted an industry survey of weld repair rates across sectors: average repair rates for Oil & Gas and Power industries range from 1 to 3%, with peak rates reaching 25% in specific locations and exceptional values documented at 55% in the worst cases. The major contributing factors are welder skill variability, weld accessibility, and poor joint fit-up prior to welding. A well-written, well-followed WPS directly addresses welder variability \u2014 it removes guesswork from the equation and sets a repeatable floor for weld quality.<\/p>\n

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\ud83d\udca1<\/span> Do You Always Need to Write Your Own WPS?<\/strong><\/div>\n

Not always. The American Welding Society publishes Standard Welding Procedure Specifications (SWPS)<\/a> \u2014 prequalified procedures for common applications using carbon steel, stainless steel, and aluminium. SWPSs are backed by published PQR data, which means a shop can adopt an SWPS and skip the testing phase entirely \u2014 provided the application falls within the SWPS’s defined scope. This is a significant time and cost saving that many smaller fabricators do not know about.<\/p>\n<\/div>\n

Essential point to understand: a welding procedure specification is not an optional quality tool but a required instruction set. Its goal: to make certified production welding generic while also removing wet-blowing supervision variation.<\/p>\n

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WPS vs. PQR vs. WPQR \u2014 Understanding the Document Chain<\/h2>\n

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The three terms \u2014 WPS, PQR, and WPQR \u2014 are often used interchangeably in the field, but they are distinct documents serving different roles in the welding qualification process. Getting them mixed up is one of the fastest ways to fail a quality audit.<\/p>\n

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Document<\/th>\nWhat It Is<\/th>\nWho Uses It<\/th>\n<\/tr>\n<\/thead>\n
WPS
\nWelding Procedure Specification<\/span><\/td>\n		The instruction document. Tells the welder exactly how to make the weld: process, materials, parameters, position, preheat.<\/td>\nWelder, supervisor, inspector \u2014 daily production reference<\/td>\n<\/tr>\n
PQR
\nProcedure Qualification Record<\/span><\/td>\n		The test record. Documents the actual parameters used during a qualification test weld, plus the destructive\/NDT test results that confirm the procedure produces sound welds.<\/td>\nWelding engineer, auditor, third-party inspector \u2014 qualification evidence<\/td>\n<\/tr>\n
WPQR
\nWelding Procedure Qualification Record<\/span><\/td>\n		The European\/ISO equivalent of a PQR under ISO 15614-1. Used in EN-standard projects (European, UKCA, international).<\/td>\nEuropean inspectors, notified bodies, EN-standard projects<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

The 4-Stage WPS Qualification Method<\/h3>\n

The WPS qualification procedure is based on a 4 step sequence within ASME Section IX and AWS D1.1. It is important to master this procedure prior to writing your first WPS:<\/p>\n

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  1. Draft a pWPS(Preliminary WPS)- Once the welding is planned then draft a welding procedure in advance, with all the essential and non-essential variables set at their planned production values.<\/li>\n
  2. Weld a test coupon – Perform the pWPS conditions on a test plate or pipe coupon with the actual production materials using an approved welding operator.<\/li>\n
  3. Test & record (PQR) – Destructively test (tensile, bend, impact) & non- destructively test ( radiographic, ultrasonic, visual) test coupon, and document actual parameters and test results in the Procedure Qualification Record.<\/li>\n
  4. Issue the certified WPS – if the PQR results satisfy the Code, then produce the production WPS from this PQR as reference. This WPS becomes the contractual document for production fabrication.<\/li>\n<\/ol>\n<\/div>\n

    Key takeaway:<\/strong> The WPS and PQR are inseparable \u2014 the WPS is the instruction, the PQR is the proof. A WPS with no referenced PQR is not a qualified welding procedure under ASME or AWS Code (unless it is an approved SWPS).<\/p>\n

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    What’s Inside a WPS? The 8 Essential Sections<\/h2>\n

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    A compliant welding procedure specification must document every variable that could affect the mechanical properties and integrity of the finished weld. The Canadian Welding Bureau (CWB) Welding Procedure Guide<\/a> \u2014 one of the most detailed open references on WPS documentation \u2014 organises the required content into eight sections. Each section has a corresponding set of common errors that auditors frequently catch in the field.<\/p>\n

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