A Welding Procedure Specification (WPS) is a formal document describing

welding Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Co ...

procedures. It is an internal document used by welding companies to instruct welders (or welding operators) on how to achieve quality production welds that meet all relevant code requirements. Each company typically develops their own WPS for each material alloy and for each welding type used. Specific codes and/or engineering societies are often the driving force behind the development of a company's WPS. A WPS is supported by a Procedure Qualification Record (PQR or WPQR), a formal record of a test weld performed and rigorously tested to ensure that the procedure will produce a good weld. Individual welders are certified with a qualification test documented in a Welder Qualification Test Record (WQTR) that shows they have the understanding and demonstrated ability to work within the specified WPS.

Introduction

The following are definitions for WPS and PQR found in various codes and standards: According to the

American Welding Society The American Welding Society (AWS) was founded in 1919 as a non-profit organization to advance the science, technology and application of welding and allied joining and cutting processes, including brazing, soldering and thermal spraying. Headq ...

(AWS), a WPS provides in detail the required welding variables for specific application to assure

repeatability Repeatability or test–retest reliability is the closeness of the agreement between the results of successive measurements of the same measure, when carried out under the same conditions of measurement. In other words, the measurements are take ...

by properly trained

welder A welder is a person or equipment that fuses materials together. The term welder refers to the operator, the machine is referred to as the welding power supply. The materials to be joined can be metals (such as steel, aluminum, brass, stainles ...

s. The AWS defines welding PQR as a record of welding variables used to produce an acceptable test weldment and the results of tests conducted on the weldment to qualify a Welding Procedure Specification. For steel construction (civil engineering structures) AWS D1.1 is a widely used standard. It specifies either a ''pre-qualification'' option (chapter 3) or a ''qualification'' option (chapter 4) for approval of welding processes. The

American Society of Mechanical Engineers The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via "continuing edu ...

(ASME) similarly 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. ASME also defines welding PQR as a record of variables recorded during the welding of the test

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. The record also contains the test results of the tested specimens. The

Canadian Welding Bureau The Canadian Welding Bureau is a certification and registration organization for companies involved in the welding of steel structures. Welders in Canada are required to be retested every two years by the Canadian Welding Bureau. The CWB Group w ...

, through CSA Standards W47.1, W47.2 and W186, specifies both a WPS and a Welding Procedure Data Sheet (WPDS) to provide direction to the welding supervisor, welders and welding operators. The WPS provides general information on the welding process and material grouping being welded, while the WPDS provides specific welding variables/parameter/conditions for the specific weldment. All WPS and WPDS must be independently reviewed and accepted by the

prior to use. These CSA standards also define requirements for procedure qualification testing (PQT) to support the acceptance of the WPDS. A record of the procedure qualification test and the results must be documented on a procedure qualification record (PQR). All PQTs are independently witnessed by the

. In Europe, the

European Committee for Standardization The European Committee for Standardization (CEN, ) is a public standards organization whose mission is to foster the economy of the European Single Market and the wider European continent in global trading, the welfare of European citizens an ...

(CEN) has adopted the ISO standards on welding procedure qualification (ISO 15607 to ISO 15614), which replaced the former European standard EN 288. EN ISO 15607 defines a WPS as "A document that has been qualified by one of the methods described in clause 6 and provides the required variables of the welding procedure to ensure repeatability during production welding". The same standard defines a ''Welding Procedure Qualification Record'' (WPQR) as "Record comprising all necessary data needed for qualification of a preliminary welding procedure specification". In addition to the standard WPS qualification procedure specified in ISO 15614, the ISO 156xx series of standards provides also for alternative WPS approval methods. These include: ''Tested welding consumables'' (ISO 15610), ''Previous welding experience'' (ISO 15611), ''Standard welding procedure'' (ISO 15612) and ''Preproduction welding test'' (ISO 15613). In the oil and gas pipeline sector, the

American Petroleum Institute The American Petroleum Institute (API) is the largest U.S. trade association for the oil and natural gas industry. It claims to represent nearly 600 corporations involved in extraction of petroleum, production, oil refinery, refinement, pipeline ...

API 1104 standard is used almost exclusively worldwide. API 1104 accepts the definitions of the American Welding Society code AWS A3.0.API 1104: "Welding of pipelines and related facilities", parts 3 (Definition of Terms) WPS is of two types- Prequalified WPS(pWPS) & qualified WPS.

References

List of standards

* ASME Boiler and Pressure Vessel Code section IX: "Qualification Standard for welding and brazing procedures, welders, brazers and welding and brazing operators" * EN ISO 15607: "Specification and qualification of welding procedures for metallic materials - General rules (ISO 15607:2003)" * EN ISO 15609: "Specification and qualification of welding procedures for metallic materials - Welding procedure specification (ISO 15609)", five parts. * EN ISO 15614: "Specification and qualification of welding procedures for metallic materials - Welding procedure test (ISO 15614)", 13 parts. * API 1104: "Welding of pipelines and related facilities", parts 5 (procedures) {{refend Welding

Introduction

See also

References

List of standards