Pipe Welding using Tungsten-Arc Gas Shielded Welding — SEG Awards Vocationally-Related Qualification Design and Technology Revision

    This topic covers the skills and knowledge required for pipe welding using Tungsten-Arc Gas Shielded Welding (TAG). It includes health and safety, equipmen

    Topic Synopsis

    This topic covers the skills and knowledge required for pipe welding using Tungsten-Arc Gas Shielded Welding (TAG). It includes health and safety, equipment selection, welding parameters, joint preparation, and practical welding of pipe assemblies.

    Key Concepts & Core Principles

    Exam Tips & Revision Strategies

    Common Misconceptions & Mistakes to Avoid

    Examiner Marking Points

    Pipe Welding using Tungsten-Arc Gas Shielded Welding

    SEG AWARDS
    vocational

    This topic covers the skills and knowledge required for pipe welding using Tungsten-Arc Gas Shielded Welding (TAG). It includes health and safety, equipment selection, welding parameters, joint preparation, and practical welding of pipe assemblies.

    1
    Learning Outcomes
    3
    Assessment Guidance
    3
    Key Skills
    1
    Key Terms
    5
    Assessment Criteria

    Assessment criteria

    SEG Awards Level 3 Diploma in Welding Techniques and Skills

    Topic Overview

    The SEG Awards Level 3 Diploma in Welding Techniques and Skills is an advanced vocational qualification designed for students who have already mastered basic welding and wish to develop professional-level competence. This diploma covers a wide range of welding processes, including Manual Metal Arc (MMA), Metal Inert Gas (MIG), Tungsten Inert Gas (TIG), and Flux-Cored Arc Welding (FCAW). Students learn to interpret engineering drawings, select appropriate welding parameters, and produce high-quality welds in various positions (flat, horizontal, vertical, and overhead). The course also emphasises health and safety regulations, non-destructive testing (NDT) methods, and quality assurance procedures, preparing learners for roles such as coded welder, welding inspector, or fabrication supervisor.

    This qualification is part of the wider Design and Technology curriculum, bridging the gap between theoretical engineering principles and practical workshop skills. It is particularly relevant for students pursuing careers in construction, manufacturing, oil and gas, or automotive industries. By completing this diploma, students demonstrate the ability to work to industry standards such as BS EN ISO 9606 and AWS D1.1, making them highly employable. The course also develops problem-solving skills, attention to detail, and the ability to work under pressure—all essential for success in professional welding environments.

    MasteryMind's resources for this diploma break down complex welding techniques into manageable learning steps. We provide detailed guides on weld defects, distortion control, and material preparation, alongside interactive quizzes and virtual simulations. Our content is aligned with the latest SEG Awards syllabus, ensuring students are fully prepared for both practical assessments and written exams. Whether you are aiming for a career as a coded welder or looking to advance your skills, this diploma is your gateway to becoming a certified welding professional.

    Key Concepts

    Core ideas you must understand for this topic

    • →Welding Positions and Techniques: Master all four main positions (1G/PA flat, 2G/PC horizontal, 3G/PF vertical, 4G/PE overhead) for MMA, MIG, and TIG processes. Each position requires adjustments to travel speed, torch angle, and filler metal deposition to ensure proper fusion and penetration.
    • →Weld Defects and Prevention: Identify common defects like porosity (caused by gas entrapment), slag inclusion (from incomplete flux removal), undercut (excessive current), and lack of fusion (insufficient heat). Understand how to adjust parameters (current, voltage, travel speed) and technique to prevent them.
    • →Non-Destructive Testing (NDT): Understand methods such as visual inspection, dye penetrant testing, magnetic particle inspection, and ultrasonic testing. Know how to interpret results and identify acceptable weld quality according to standards like BS EN ISO 5817.
    • →Welding Symbols and Drawings: Read and interpret engineering drawings including weld symbols (e.g., fillet, butt, plug welds) and dimensions. Understand arrow side, other side, and field weld symbols as per BS EN ISO 2553.
    • →Material Preparation and Distortion Control: Learn to clean and bevel edges, preheat materials (e.g., for thick carbon steel), and use tack welds, back-step welding, and clamping to minimise distortion. Understand how heat input affects the heat-affected zone (HAZ).

    Learning Objectives

    What you need to know and understand

    • 1.1. Identify the roles of various organisations involved with health and safety in the workplace, to include:• Health and Safety Executive (HSE)• Environmental Health• Local Authorities1.2. Identify the roles of various individuals involved with health and safety in the workplace, to include:• Company safety officers• Company safety representatives• Environmental health officers• HSE inspectors1.3. Identify the purpose and typical contents of an Organisations health and safety policy1.4. Describe the purpose of a risk assessment, to include:• who should carry out risk assessments• when to carry out a risk assessment• identification of the 5 steps of risk assessment1.5. Identify the precautions to be taken when working in high risk areas, to include:• risk assessments• permits to work• high/low temperature working conditions• lock off systems• isolation of equipment1.6. Describe the control and safe removal of welding fumes and gases created during the welding process, to include:• natural extraction• local extraction• PPE and specialist breathing equipment1.7. Identify the risk associated with pipe welding on site, to include:• location• environmental (wind, rain etc.)• availability of power supply• working/welding in trenches• welding at heights1.8. Identify the different power sources used when welding with MMA, MAGS and TAG welding, to include:• transformer• generator• rectifier• invertor1.9. Describe features of the power sources as listed in 2.1, to include:• type of current produced (AC/DC) • maintenance requirements• portability• suitable applications 1.10. Identify specialist equipment used when carrying out pipe welding activities, to include:• pipe cutting equipment• jigs/fixtures• turntables/rotators/manipulators1.11. Describe the importance of correct storage conditions for electrodes, wires and gas cylinders, to include:• location• ventilation• contamination• labelling 1.12. Identify the use of different types of electrodes, electrode wires and filler wires when carrying out pipe welding activities1.13. Identify the range and application of shielding gases and gas mixtures used when pipe welding with the MAGS or TAG welding process1.14. Describe the effects of using damaged or corroded electrodes, electrode wires and filler wires when carrying out pipe welding activities1.15. Identify and select the required welding parameters to be used when welding low carbon steel pipes using MMA, MAGS and TAG welding processes, to include:• welding voltage• welding current• electrode polarity• wire feed speed• torch slope and tilt angles• electrode extension• speed of travel• inductance• gas delay system• shielding gas type• shielding gas flow rate (LPM)1.16. Identify suitable welding preparations for the type of joint, diameter and wall thickness of the pipe being welded, to include:• included angle• angle of bevel• root face dimension• root gap dimension1.17. Identify different types of joints used in pipe work assemblies, to include:• butt welds• branch joints• slip on flange• set on flange1.18. Describe the advantages and limitations of the methods listed that are used to produce suitable welding preparations on materials, to include:• thermal methods• mechanical (chip forming)• bevelling machines• abrasive methods1.19. Identify the application of both permanent and temporary backing rings used in pipe welding1.20. Identify methods used to ensure pipe alignment before and during welding activities1.21. Identify different types of pipe work fittings, to include:• concentric reducers• eccentric reducers• equal diameter tee pieces• unequal diameter tee pieces• elbows 45° 60° 90°• blank ends (dished ends)1.22. Identify appropriate safety checks on the selected welding equipment prior to use1.23. Select suitable welding parameters to enable the listed joints (given in 6.3.) to be welded by one process from the following:• MMA welding• MAGS welding• TAG welding1.24. Weld No 1 – single vee pipe butt weld – rotated. Weld No 2 – s

    Assessment Criteria

    Key criteria assessors look for in your portfolio

    • Identify health and safety roles and risk assessment steps.
    • Select appropriate welding parameters for TAG welding of pipes.
    • Prepare pipe joints correctly including bevel angles and root gaps.
    • Demonstrate safe and competent TAG welding on pipe butt joints.
    • Inspect welds for quality and identify defects.

    Assessment Guidance

    Guidance for achieving higher grades

    • 💡Memorise typical welding parameters for common pipe sizes.
    • 💡Practise setting up and adjusting TAG equipment quickly.
    • 💡Understand the effects of different shielding gases on weld quality.
    • 💡Tip 1: In practical assessments, always perform a visual inspection of your weld before calling the examiner. Check for uniform bead width, proper reinforcement height, and no visible defects. This shows you are quality-conscious and can self-evaluate.
    • 💡Tip 2: When answering theory questions, use correct terminology (e.g., 'arc length' not 'gap', 'travel angle' not 'angle'). Reference specific standards (e.g., BS EN ISO 9606) and explain how parameters affect weld properties. This demonstrates depth of knowledge.
    • 💡Tip 3: For written exams on weld defects, always state both the cause and the remedy. For example: 'Porosity is caused by gas shielding disruption; remedy is to check gas flow rate and ensure no drafts.' This shows you understand the full problem-solving process.

    Common Mistakes

    Common errors to avoid in your coursework

    • Confusing TAG with MAGS or MMA welding processes.
    • Incorrectly setting gas flow rate or electrode extension.
    • Neglecting pre-weld safety checks on equipment.
    • Misconception: 'MIG welding always produces stronger welds than MMA.' Correction: While MIG is faster and easier for thin materials, MMA often provides deeper penetration and is better for thick sections or outdoor work. The choice depends on material thickness, position, and environmental conditions.
    • Misconception: 'If the weld looks good on the surface, it is strong enough.' Correction: Surface appearance does not guarantee internal quality. Defects like lack of fusion or slag inclusion can be hidden. Always follow welding procedure specifications (WPS) and use NDT to verify integrity.
    • Misconception: 'You can weld any metal with the same settings.' Correction: Different metals (carbon steel, stainless steel, aluminium) have different thermal conductivity, melting points, and reactivity. For example, aluminium requires AC TIG with high-frequency start and a different filler rod (e.g., ER4043).

    Frequently Asked Questions

    Common questions students ask about this topic

    Before You Start

    Prior knowledge that will help with this topic

    • •Basic Health and Safety in Welding: Understanding of PPE (welding helmet, gloves, fire-resistant clothing) and workshop safety protocols (fire extinguishers, ventilation, fume extraction).
    • •Fundamental Welding Skills: Ability to run a straight bead in flat position using MMA or MIG. Familiarity with setting up welding equipment (current, wire feed speed, gas flow).
    • •Basic Engineering Drawing: Knowledge of orthographic projection, dimensions, and simple weld symbols. Ability to read a workshop drawing to identify joint types and weld sizes.

    Key Terminology

    Essential terms to know

    • 1.1. Identify the roles of various organisations involved with health and safety in the workplace, to include:• Health and Safety Executive (HSE)• Environmental Health• Local Authorities1.2. Identify the roles of various individuals involved with health and safety in the workplace, to include:• Company safety officers• Company safety representatives• Environmental health officers• HSE inspectors1.3. Identify the purpose and typical contents of an Organisations health and safety policy1.4. Describe the purpose of a risk assessment, to include:• who should carry out risk assessments• when to carry out a risk assessment• identification of the 5 steps of risk assessment1.5. Identify the precautions to be taken when working in high risk areas, to include:• risk assessments• permits to work• high/low temperature working conditions• lock off systems• isolation of equipment1.6. Describe the control and safe removal of welding fumes and gases created during the welding process, to include:• natural extraction• local extraction• PPE and specialist breathing equipment1.7. Identify the risk associated with pipe welding on site, to include:• location• environmental (wind, rain etc.)• availability of power supply• working/welding in trenches• welding at heights1.8. Identify the different power sources used when welding with MMA, MAGS and TAG welding, to include:• transformer• generator• rectifier• invertor1.9. Describe features of the power sources as listed in 2.1, to include:• type of current produced (AC/DC) • maintenance requirements• portability• suitable applications 1.10. Identify specialist equipment used when carrying out pipe welding activities, to include:• pipe cutting equipment• jigs/fixtures• turntables/rotators/manipulators1.11. Describe the importance of correct storage conditions for electrodes, wires and gas cylinders, to include:• location• ventilation• contamination• labelling 1.12. Identify the use of different types of electrodes, electrode wires and filler wires when carrying out pipe welding activities1.13. Identify the range and application of shielding gases and gas mixtures used when pipe welding with the MAGS or TAG welding process1.14. Describe the effects of using damaged or corroded electrodes, electrode wires and filler wires when carrying out pipe welding activities1.15. Identify and select the required welding parameters to be used when welding low carbon steel pipes using MMA, MAGS and TAG welding processes, to include:• welding voltage• welding current• electrode polarity• wire feed speed• torch slope and tilt angles• electrode extension• speed of travel• inductance• gas delay system• shielding gas type• shielding gas flow rate (LPM)1.16. Identify suitable welding preparations for the type of joint, diameter and wall thickness of the pipe being welded, to include:• included angle• angle of bevel• root face dimension• root gap dimension1.17. Identify different types of joints used in pipe work assemblies, to include:• butt welds• branch joints• slip on flange• set on flange1.18. Describe the advantages and limitations of the methods listed that are used to produce suitable welding preparations on materials, to include:• thermal methods• mechanical (chip forming)• bevelling machines• abrasive methods1.19. Identify the application of both permanent and temporary backing rings used in pipe welding1.20. Identify methods used to ensure pipe alignment before and during welding activities1.21. Identify different types of pipe work fittings, to include:• concentric reducers• eccentric reducers• equal diameter tee pieces• unequal diameter tee pieces• elbows 45° 60° 90°• blank ends (dished ends)1.22. Identify appropriate safety checks on the selected welding equipment prior to use1.23. Select suitable welding parameters to enable the listed joints (given in 6.3.) to be welded by one process from the following:• MMA welding• MAGS welding• TAG welding1.24. Weld No 1 – single vee pipe butt weld – rotated. Weld No 2 – s

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