Jul 20, 2018
WPS and PQR Demystified
Several members of the Education Services team at AWS recently had the opportunity to attend a handful of instructor-led CWI seminars. During that time, we were able to interact with the students and get some insight into how things were going for them. Collectively, we found that most students were at least somewhat familiar with the majority of the information that was being covered during the seminar. However, there was one topic that drew a complete blank from students time and time again: Welding Procedure Specifications and Procedure Qualification Records.
“What is a WPS?” “What is a PQR?” “Why are they important?” “How do I use them?”
If these questions have you shrugging your shoulders as well, don’t worry, we’re about to break these confusing acronyms down for you a bit. Building on our popular four-part Welding Symbols Demystified series (Part I, Part II, Part III, Part IV), let’s tackle WPSs and PQRs.
What is a WPS?
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. In the same way that a recipe for a cake details what ingredients and quantities you’ll need, a WPS contains details that are necessary to create the desired weld. This includes information such as base metal grade, filler metal classification, amperage range, shielding gas composition, and pre-heat and interpass temperatures. The idea is that if a group of welders adhere to all the details on a WPS, they should each be able to produce welds with reasonably similar mechanical properties.
What is a PQR?
To answer this question, we need to take a step back. You see, before a WPS can be drafted, a preliminary set of procedures and materials must be established. This initial procedure is used to create a series of welds which are then mechanically tested to ensure they meet all applicable requirements. The procedures for creating and testing the sample welds, as well as the final results, are documented on a Procedure Qualification Record, or PQR. If the test results are acceptable, the PQR is approved and can then serve as the foundation on which one or more WPSs are drafted. In short, a PQR serves as evidence that a given WPS can, in fact, be used to produce an acceptable weld.
What's the Importance of a WPS and PQR?
For starters, WPSs and PQRs are the blueprints for creating welds in a repeatable, efficient, and safe manner. If you need more proof that WPSs and PQRs are a big deal, look no further than the Body of Knowledge for the CWI exam. This document offers an approximate breakdown of the topics that are covered in each part of the test. Part B focuses on the practical application of inspection, and is widely referred to as the hands-on portion of the exam. You’ll notice that at least 28% of the Part B questions relate to Procedure and Welder Qualifications. In order to answer these questions, you’ll need to know how to read WPSs and PQRs, extract pertinent information from them, and make assessments based off that information. I can tell you that the CWI seminar instructors do a fine job covering WPSs and PQRs from firsthand experience. However, if the first time you lay eyes on a WPS is during the CWI seminar, or worse yet, the CWI exam itself, you’re really digging yourself into a hole.
Pro tip: If this is ringing especially true for you, feel free to check out the sample WPSs and PQRs in the AWS Book of Specifications. They can be found in the annexes toward the tail end of the document.
How Do I Use a WPS and PQR?
That’s a great question. It’s also one that warrants considerably more time and detail than I can provide in this venue. As I mentioned earlier, WPSs and PQRs are covered rather extensively during the live CWI seminars. However, if you’re looking to get a leg up, then you may want to consider AWS Learning’s “WPS/PQR: Explained” interactive online course. This course was created in response to continued feedback from students and educators, and covers the ins and outs of welding procedure specifications and procedure qualification records. This includes everything from what their purpose is, how they are drafted, what kinds of information they contain, and how to make use of that information.
The course also covers the procedure qualification process, including detailed information on material properties as well as common nondestructive and destructive tests. The instruction throughout this course is presented in a series of short modules, allowing you to internalize information bit by bit, instead of all at once. Each module builds on concepts introduced in the previous one, and includes quizzes and interactive practice questions to help you really get a grasp of the material.
So, Now What?
It’s important to keep in mind that we’re just scratching the surface here. WPSs and PQRs are an important part of a CWI’s knowledge base, but they’re far from the only thing. With that in mind, if you’re ready to take the next step and learn more about WPSs and PQRs, be sure to check out the “WPS/PQR: Explained” page at AWS Learning. While you’re there, you may want to check out some of our other educational offerings as well. Whether you’re looking to learn about a new topic, or brush up on one you’re already familiar with, AWSL’s suite of online courses is a great place to start.
As always, if you have any questions, or if you have a suggestion for a topic you’d like us to discuss in an upcoming blog, give us a call or drop us a line in the comments section below!