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Prequalified Welding Procedure and Qualified Welding Procedure
Commonly overlooked steps in developing a welding procedure

Developing a Welding Procedure Specification (WPS) involves much more than selecting amperage and voltage—it requires a structured approach to ensure weld quality and consistency. The process begins with understanding the base metal’s properties and how it responds to heat, followed by selecting the most suitable welding process for quality and productivity. Choosing the correct filler metal and joint design are equally critical, as both influence weld strength, cost, and efficiency. Proper control of preheat and post-weld heat treatment (PWHT) helps manage metallurgical changes that prevent cracking or distortion. Finally, setting appropriate welding variable ranges ensures balance between quality and productivity, resulting in a reliable, code-compliant welding procedure.

Frequently Asked Questions About Prequalified Welding Procedures (Stainless Steel)

This post provides answers to frequently asked questions regarding the "280 Prequalified Welding Procedures for Stainless Steel" product. It addresses common inquiries from customers about the digital format, permissible uses for CWIs, distinctions between qualified and prequalified procedures, and the rationale behind the product's affordability. Additionally, it clarifies compliance with AWS D1.6, modification flexibility, and how included guides facilitate proper use and customization of these welding procedures.

welding procedure development
How to write AWS D1.1 Prequalified Welding Procedure Specifications

The AWS D1.1 Structural Welding Code for Steel allows fabricators to use prequalified welding procedures (WPSs), saving significant time and money by exempting them from testing. This post outlines an 8-step guide to writing a prequalified WPS, covering selecting approved base metals, weld joints, welding processes, filler metals, shielding gases, and determining preheat, interpass, and post-weld heat treatment. It emphasizes that anyone who understands the code can create these essential documents for quality and productivity.

welding procedure development
Welding Procedure Development: Qualification

This blog post concludes a series on developing welding procedures by discussing the crucial topic of qualification. Qualification involves performing both destructive and non-destructive tests to ensure a procedure can produce sound welds, typically following the requirements of specific codes like AWS D1.1. An alternative to this rigorous testing is prequalification, which allows the user to forgo testing if all the requirements of the applicable code's prequalification clause are met. Regardless of the method, the document emphasizes the importance of verifying and documenting the suitability of all developed welding procedures for future reference and quality assurance.

Welding Procedure Development
Welding Procedure Development: Selecting Welding Parameters

Amperage, voltage, travel speed, and other key variables are crucial for creating a robust welding procedure that ensures sound and high-quality welds.Blog Post Summary This blog post explains the importance of key welding parameters when developing a welding procedure specification. It details how amperage (current) directly influences weld penetration and productivity, while voltage primarily affects bead shape and width. The post also highlights that travel speed is critical, as it impacts weld size, heat input, penetration, and overall weld quality. Additionally, it covers the significance of travel and transverse angles, noting their effects on weld shape and potential for defects. Finally, the post emphasizes the often overlooked but critical role of Contact Tip to Work Distance (CTTWD), explaining how it can drastically alter amperage and potentially lead to a non-compliant or defective weld if not properly controlled.

Prequalified Welding Procedure and Qualified Welding Procedure
Understanding the Difference between Qualified and Prequalified Welding Procedures

One of the most common questions in welding is whether qualified or prequalified welding procedures are better. Both serve the same purpose — ensuring consistent, high-quality welds — but they achieve it in different ways. Qualified procedures are proven through destructive and nondestructive testing, while prequalified procedures skip testing if strict code requirements are followed. Prequalified procedures save time and money upfront, but qualified procedures can sometimes reduce weld volume and cut long-term fabrication costs. In this post, we explain both approaches, the requirements for each, and when to use one over the other to get the best results for your shop.