WPS vs PQR
After watching this video you will be able to write a welding procedure specification (WPS) on your own. A welding procedure must be qualified in accordance with the requirements of an appropriatewelding procedure standard, such as ASME Sec IX, as follows:1. Produce a welding procedure specification (WPS) as stated above.2. Weld a test piece in accordance with the requirements of your specification. A Welding Procedure Specification, or WPS, is a document that serves as a guide for the effective creation of a weld that meets all applicable code requirements and production standards. Think of a WPS as a recipe for welders.
“WPS” (Welding Procedure Specification) and “PQR” (Procedure Qualification Record) are documents that refer to the practice of welding.
WPS is a set of welding instructions. It aids in planning and ensuring quality control of the welded product as well as future reproductions of the product. Welding parameters, such as joint design, position, base metals, electrical characteristics, filler metals, technique, shielding, preheat, and post-weld heat treatment are all detailed in the WPS document.
WPS further explains the rules and details of the test and how the pieces should be assembled. Simply put, a WPS is like a blueprint for welders to produce the same quality of welded product over and over again.
Product Qualification Record is another type of document that also refers to welding. However, unlike WPS, the PQR document’s purpose is to serve as a checklist or record of compliance regarding the standard requirements of an appropriate welding procedure.
The PQR form covers all the welding parameters in the WPS document. In addition, it also includes some observations or other matters regarding welding procedures and specific tests like tensile tests and guided bend tests. It may also show the visual inspection and fillet weld test results.
Another important component of the PQR is the disclosure of relevant information, such as the welder’s name and the name of the person who did the inspection, and even the dates with the acknowledgment of the manufacturer or contractor.
The PQR is prepared by a qualified or licensed individual and submitted to the people concerned. The inspector will then endorse the company and its product to the industry and market.
A PQR is seen as complementary to a WPS because there are times when the PQR document is used to make a WPS document.
- Both Welding Procedure Specifications (WPS) and Product Qualification Records (PQR) are important documents in welding. Both documents are not the same but are closely related to one another. You might say they even complement each other.
- Each document, while closely related, comes with a different purpose. WPS serves as a blueprint for a written instruction or guide on how to create a welded product based on a certain standard and quality. Meanwhile, PQR is a document that checks whether the standard is being followed by inspecting and answering the document regarding specific areas and tests.
- The Welding Procedure Specification and Product Qualification Record documents have similar items in their body, specifically the welding parameters. In a WPS, the welding parameters are explained in the context of instructions. The purpose is to make the welder reproduce the product with a particular quality and standard. On the other hand, PQR uses these welding parameters as a checklist to see if the standard is met or not.
- The PQR is a standard document, but the people who use it may not necessarily come from the same background. Welders and engineers who create the welded product often peruse a WPS to make the product comply with the standard quality. In contrast, the PQR is often associated with inspectors, manufacturers, or contractors who use the document for testing and verification purposes.
- Another difference is the orientation of the document’s contents. A WPS is usually filled with numerous texts, images, and sentences in accordance to its being an instructional guide. On the other hand, a PQR is like a checklist with blank lines and spaces for written notes that will be filled out by the inspector during the inspection.
- Before the inspection, the WPS document is the object of attention of the welders. Meanwhile, during and after the inspection, the PQR is the document of concern for inspectors, contractors/manufacturers, and welders.
- Differences Between Fraternity And Sorority - January 8, 2014
- Differences Between Lucite and Plastic - January 7, 2014
- Differences Between Oil and Butter - January 6, 2014
This information is intended for those of you who would like to get familiar with process and performance of approvals. Its does relate to the following codes and specification, but is not limited to them: ISO 15614, ISO 15613, ASME Sect. IX, AWS D1.1, AWS D1.2, AWS D1.3, AWS D1.6, AWS D15.1, and others.
First we consider the approval flow and concepts of ISO 15607 (Specification and qualification of welding procedures for metallic materials – General rules / Note: ISO 15607 is applicable to manual, mechanized and automatic welding.) for the qualification of WPS, a good understanding of the relationship between different documents and their purpose can be outlined.
Welding is considered a special process in the terminology of standards for quality systems. Standards for quality systems usually require that special processes be carried out in accordance with written procedure specifications.
Welding procedure specifications are needed in order to provide a well-defined basis for planning of the welding operations and for quality control during welding. The preparation of a welding procedure specification (WPS) provides the necessary basis for fulfilling the applicable requirements, but it does not in itself ensure that the welds fulfil the requirements. Some deviations, notably imperfections and distortions, can be evaluated by nondestructive methods on the finished product, however, at time the applied NDE methods will not provide the essential testing results to document that a weld meets all acceptance criterion and hence engineering requirements.
Metallurgical deviations constitute a special problem, however, because non-destructive evaluation of the mechanical properties is impossible at the present level of non-destructive technology, this has resulted in the establishment of a set of rules for qualification of the welding procedure prior to the release of the specification to actual production.
According to ISO 15607, the manufacturer shall prepare a preliminary WPS (pWPS) and shall ensure that it is applicable for the actual production, using experience from previous productions and the general fund of knowledge of welding technology.
Each pWPS shall be used as a basis for the establishment of WPQR, qualified according to an acceptable method of the code or specification that is / which are applicable.
If the qualification involves welding of test pieces, then the test pieces shall be welded in accordance with the pWPS.
Per ISO 15607, the WPQR shall include all variables (essential, supplement and non-essential), as well as the specified ranges of qualification given in the appropriate standard. On basis of the WPQR, the WPS for production welding is developed under the responsibility of the manufacturer and its experts unless otherwise required.
Information Flowchart related to ISO 15607
ASME or AWS codes/specification maintain a slightly different definition of the approval of a WPS. The range of approval, or the scope of a given WPS, is outlined in the WPS only. The WPQR does not include a range of qualification, Since it is a testing record “only”. The WPQR is the foundation for the scope or range of approval a WPS can receive.
The question why ISO includes range of approval requirements for a WPQR is an ongoing discussion amongst experts. The ISO System (or EN for that matter) considers a WPS to be issued to support a specific welding application. The actual WPS range of approval might therewith be limited. With that said, the WPQR would provide possibilities, whereas the WPS is limits / restricts those essential, supplement and non-essential variables that apply to a given production need.
Information Flowchart related to ASME / AWS
At this point it is important to touch on one very important subject, which also creates discussions most often! Who defines the “true” range of approval for a given WPS? The quick answer is that the applicable code or specification outline the requirements for the range settings and information applicable to a WPS. As much this statement is true, as much it is not! If a manufacturer would indeed test the entire possible range of a WPS, it is likely that at times a sound weld cannot be placed or the welding conditions would indeed fall outside of the applicable code or specification. For instance, what often can be found is that a WPS is issued with a range in welding parameter that would result in a change of a transition mode. At times, multiple transition modes were not considered during the approval of the WPQR / WPS.
An additional consideration is the range of approval for welding positions. Even though many codes support the qualification range to be rather large, however, at times it is not possible to weld “out of position” with the given range in welding parameter. With that said, who truly is the one to determine the range of approval of a WPS?
Most, if not all, codes and specification require the approval by the responsible engineer, welding engineer, expert, supervisor or welding coordinator (definition depending on the applicable code / specification). The assigned expert shall have the knowledge to determine, if a possible range of approval is truly the range that leads to the desired / required acceptable weld.
Depending on the knowledge about and level of engagement in the science of welding, the approval of the maximum possible range or scope of a WPS might be applied; or it is limited to a specific case.
On a Personal Note: Even though a code or specification promotes a certain range of WPS qualification, it may not be suitable for the intended welding application.
We hope that the information in this WWW page provides some value and maybe discussion point. Feel free to send us an email to this rather interesting conversation! ([email protected]).
Wps Wpqr Welding Procedure Tool
Important: Some of the wording is rather similar or identical to what is referenced in codes and standards. This outline does not claim total compliance or a flawless identity with welding codes or specification.
We have worked with over 400 companies in Asia, Europe and North America, to achieve either compliance with national of international certifications / approvals, or to implement sound welding systems or processes.
- Q&A Inspection
- Weld Joint Classification
- Welding Coordination
- Welding drawing requirements (i.e. welding detail review, weld seam quality review and support
- Weld mapping and log preparation
- Material identification and traceability
- Welding qualification program
- Development of welding procedure approval plans
- Review and evaluation of existing approvals
- Global Weld Management Software
Wpqr Welding Definition
Welder Training and Certification
- Welding operator qualifications
- Welding operator approvals
- Welder training
- NDE training
- QM system training
- Inspection of welds
ECE Global witnesses the testing and validates that the welding of test samples, as well as procedure and considerations to do so, meet the applicable standards and requirements. ECE Global does not provide any judgement, if the process/procedure are sound and suitable for the intended application, which is the responsibility of the process owner.
All destructive and non-destructive testing (with the exception of a visual inspection that will be performed by ECE Global and the customer), will be performed by an ISO 17025 certified third party testing laboratory. The 3rd party testing laboratory will provide a test report, which details the result of the testing they have performed.
ECE Global will review the test reports to check and validate that the reported test results meet the applicable standards (e.g. customer specification, industrial standards). ECE Global will issue a report (Welding Procedure Qualification Record (WPQR)), to document the conditions during the welding process, as well as to summarize the testing results provided by the 3rd party testing laboratory. ECE Global will report to the customer if all collected information meet, or do not meet, the applicable specification. ECE Global will provide the applicable report to the customer, who is obligated to review the report and sign it for compliance. Thus ECE Global acts as a witness and not approver.
Our Terms and Conditions apply