Lesson 4: WELDING IV – welding processes, key welding standards
In this lesson, we will explore key welding standards that are essential for ensuring the quality and reliability of welding processes.
- Introduction to Welding Standards
- Welding standards are vital guidelines designed to maintain the quality and integrity of welding processes.
- These standards encompass various aspects of welding, from the qualifications of welders to the quality of welded structures.
- EN ISO 14731: Welding Coordination
- Proper coordination and control of welding activities are crucial for achieving weld quality.
- EN ISO 14731 outlines the activities, tasks, and responsibilities related to welding processes.
- This standard ensures that welders are well-trained and qualified to perform their tasks.
- Welders must pass a welding qualification exam, including theoretical and practical components, to prove their skills.
- The qualification is valid within the specified period and must be annually validated by the responsible welding personnel.
- Welder qualifications are specific and depend on factors such as welding procedure, material type, dimensions, quality group of the material, type of welded joint, and manufacturing conditions.
- The EN ISO 9606 series of standards defines the requirements for the qualification of welders, covering various materials including steels, aluminium, copper, nickel, titanium-zirconium, and their alloys.
- Welding Procedure Specification (WPS) and Welding Procedure Qualification Report (WPQR)
- Welders receive work instructions for specific welds through a WPS (Welding Procedure Specification).
- A WPQR (Welding Procedure Qualification Report) is generated through a process test that follows the WPS specifications.
- The WPQR serves as the basis for creating welding instructions for similar tasks.
- Specifications for the qualification of welding technology are provided in the EN ISO 15609 standard.
- Quality Levels of Imperfections (EN ISO 5817)
- No weld is perfect, and imperfections are inevitable.
- EN ISO 5817 classifies imperfections in welds, including gas porosity, slag inclusion, misalignment, undercut, lack of fusion, and cracking.
- Seams are categorized into three levels: D (moderate), C (medium), and B (increased).
- The standard sets limits for imperfections in each category, and imperfections exceeding these limits are considered defects that must be repaired.
- EN ISO 13920: Quality of Welded Structures
- EN ISO 13920 addresses the overall quality of welded structures, including their size and shape accuracy.
- It distinguishes several quality classes, such as A, B, C, D for length and angles, and E, F, G, H for straightness, flatness, and parallelism.
- Drawing Marks for Welds (EN ISO 2553)
- Welding drawings play a critical role in specifying the location, type, continuity, and discontinuity of welds, as well as welding procedures and necessary tests.
- EN ISO 2553 standard provides guidelines for the drawing marks used in welding drawings.
- Staying Current with Standards
- Welding standards may evolve over time to align with changing technology and industry needs.
- Professionals involved in welding must stay updated with the latest standard specifications.
- New standards are issued with a commencement date of validity, and previous versions are withdrawn.
- It is essential to follow the requirements of the standards in effect to ensure compliance and quality in welding processes.
- Understanding and adhering to welding standards are critical for maintaining the quality and reliability of welding processes.
- These standards cover various aspects, from welder qualifications to imperfection limits and structural quality.
- Professionals in the welding industry must keep abreast of changes in standards to ensure the highest standards of safety and quality.
In this lesson, you’ve gained insights into the key welding standards that govern welding processes. These standards are essential for maintaining weld quality and ensuring the integrity of welded structures.