Welding pipe/tube using multiple manual arc welding processes
Overview
This standard identifies the competencies you need to produce full penetration butt welds in pipe or tube using manual welding processes such as manual metal arc (MMA), MIG, MAG, TIG, Plasma arc or cored wire welding equipment in accordance with instructions and/or approved welding procedures. It covers the use of multiple welding processes such as root TIG and fill with MMA or MMA root and flux core fill. You will be required to check that all the work holding equipment and manipulating devices required are available and in a usable condition. You will be expected to set up the welding equipment ensuring that all the leads/cables, hoses and wire feed mechanisms are securely connected and free from damage. In preparing to weld you will need to set and adjust the welding conditions in line with the welding procedure specification. You must operate the equipment safely and correctly and make any necessary adjustments to settings in order to produce the welded joints to the required specification.
Your responsibilities will require you to comply with organisational policy and procedures for the welding activities undertaken and to report any problems with the welding equipment or welding activities that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work with minimum supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you produce.
Your underpinning knowledge will provide a good understanding of your work, and provide an informed approach to applying welding procedures and instructions. You will understand the welding process used and its application, and will know about the equipment, materials and consumables used in adequate depth to provide a sound basis for setting up and operating the equipment, recognising and correcting faults and ensuring the work output is produced to the required specification. Visual inspection and non-destructive testing of your completed work is implied. You will understand the safety precautions required when working with the welding equipment. You will be required to demonstrate safe working practices throughout, and will understand the responsibility you owe to yourself and others in the workplace.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- follow the relevant joining procedure and job instructions
- check that the joint preparation complies with the specification
- check that joining and related equipment and consumables are as specified and fit for purpose
- produce joints as specified using the appropriate thermal joining technique
- produce joints of the required quality and of specified dimensional accuracy
- shut down the equipment to a safe condition on completion of joining activities
- deal promptly with excess and waste materials and temporary attachments, in line with approved and agreed procedures
- deal promptly and effectively with problems within your control and report those that cannot be solved
Knowledge and Understanding
You need to know and understand:
- the safe working practices and procedures to be observed when working with the selected welding equipment (general workshop and site safety; appropriate personal protective equipment (PPE); fire prevention; protecting other workers from the effects of the welding arc; safety in enclosed/confined spaces; fume control; accident procedure; statutory requirements, risk assessment procedures and relevant requirements of HASAWA, COSHH and Work Equipment Regulations; safe disposal of waste materials)
- the correct handling and storage of gas cylinders (manual handling and use of cylinder trolley, leak detection procedures, relevant BCGA codes of practice, cylinder identification, gas pressures, cylinder and equipment safety features, emergency shutdown procedures)
- the hazards associated with the selected welding process and how they can be minimised (live electrical components, poor earthing, arc radiation, EMF, fumes and gases, gas supply leaks, spatter, hot slag and metal; grinding and mechanical metal/slag removal; elevated working; enclosed spaces; slips, trips and falls)
- the manual welding process selected and an awareness of the different types of welding equipment (basic principles of fusion welding, AC and DC power sources, ancillary equipment, power ranges, care of equipment, terminology used in welding, flame setting)
- extracting information required from drawings and welding procedure specifications (interpretation of welding symbols, scope, content and application of the welding procedure specification such as preheat) to include symbols and conventions to appropriate British, European or relevant International standards in relation to work undertaken
- the consumables associated with the chosen welding process (types of electrodes and or filler metal and their application; types of shielding gas and their application, gas supply and control; correct control, storage and drying of electrodes and filler wire)
- the types and features of welded joints in pipe/tube, (fillet and butt welds, single and multi-run welds, welding positions, weld quality)
- methods of setting up and restraining the joint to achieve correct location of components and control of distortion (edge preparation, use of jigs and fixtures, manipulators and positioners, tack welding size and spacing in relationship to material thickness and component size, use of temporary attachments, pre-setting)
- preparing the welding equipment and checks that need to be made to ensure that it is safe and ready to use (electrical connections, power return and earthing arrangements; equipment calibration, setting welding parameters)
- the techniques of operating the welding equipment to produce a range of joints in the various joint positions (fine tuning parameters, correct manipulation of the welding gun or electrode, safe closing down of the welding equipment)
- the importance of complying with job instructions and the welding procedure specification
- problems that can occur with the welding activities and how these can be overcome (causes of distortion and methods of control, effects of welding on materials and sources of weld defects; methods of prevention)
- the organisational quality systems used and weld standards to be achieved
- weld inspection and test procedures used including visual and non-destructive tests
- personal approval tests and their applicability to your work
- the extent of your own responsibility and whom you should report to if you have problems that you cannot resolve
Scope/range
Scope Performance
1. Prepare for the pipe/tube welding process, to include carrying out all of the following:
- obtaining the appropriate equipment for the welding activities to be carried out (type, current capacity)
- checking the condition of and correctly connecting welding leads, earthing arrangements and electrode holder
- connecting all required hoses, regulators and/or flow meters and safety devices
- setting and adjusting welding conditions/parameters, in accordance with welding procedure specification
- preparing the work area for the welding activities (such as placing welding screens, positioning fume extraction equipment)
- ensuring that the components are correctly set up with regard to specified joint preparation and secure
- obtaining and wearing appropriate personal protective equipment
2. Set up, check, adjust and use welding and related equipment for two of the following welding processes:
- Manual Metal Arc
- MIG/MAG
- TIG
- Plasma arc
- Cored wire
3. Use consumables specified in the welding procedure specification for the following: - the root run(s)
- the fill and capping runs
4. Produce full penetration butt joints in both of the following: - small bore pipe / tube (50mm diameter or less)
- large bore pipe / tube (above 50mm diameter)
5. Weld butt joints according to approved welding procedures in good access situations in the following BS EN ISO 6947 positions: - Inclined (H-LO 45 or J-LO 45)
and three other positions chosen from: - flat (PA) rotating
- horizontal (PC)
- vertical Upwards (PF)
- vertical Downwards (PG)
6. produce welded components which: - achieve a minimum weld quality acceptable to quality level B of BS EN ISO 5817 except for excessive weld metal, excessive convexity, excessive throat thickness and excessive penetration for which quality level C shall apply (for aluminium BS EN ISO10042 applies)
- meet the required dimensional accuracy within specified tolerance
Scope Knowledge
Values
Behaviours
Additional Information
You will be able to apply the appropriate behaviours required in the workplace to meet the job profile and overall company objectives, such as:
- strong work ethic
- positive attitude
- team player
- dependability
- responsibility
- honesty
- integrity
- motivation
- commitment