Blunt / Balchin Health and Safety in Welding and Allied Processes

5. Auflage 2002
ISBN: 978-1-85573-748-8
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 272 Seiten

Reihe: Woodhead Publishing Series in Welding and Other Joining Technologies

This edition of Health and safety in welding and allied processes has been extensively revised to take into recent account advances in technology and legislative changes both in the UK and USA. Beginning with a description of the core safety requirements, it goes on to describe the special hazards found in the welding environment - noise, radiation, fume, gases and so on in terms of their effects and the strategies that can be adopted to avoid them.The book takes each major joining technology in turn and discusses the key hazards that are most relevant to each process. There are chapters covering: the common arc and gas welding processes; specialised welding processes; brazing, soldering and thermal spraying; welding and flame spraying of plastics; radiographic inspection; mechanical hazards; noise and vibration; radiation; compressed gases; fume and ventilation; fire and first aid; and welding in situations of increased hazard, such as those requiring special precautions to ensure safe working on vessels contaminated by flammable materials.The aim throughout the book is to explain the hazards clearly and concisely, describe how they arise, and suggest practical methods to achieve safe working.Health and safety in welding and allied processes is an essential resource for welders, their managers and all health and safety practitioners who have welding and related processes taking place in their workplaces. - A completely revised new edition of the definitive work on welding health and safety - Provides detailed risk analysis for all the major processes - Shows how to set up effective workplace systems for risk assessment, first aid and reporting

Dr Jane Blunt is a materials engineer who spend several years at The Welding Institute (TWI) undertaking projects associated with a variety of welding processes. After being appointed safety adviser, she studied occupational health and safety and is a professional member of the Institution of Occupational Safety and Health. She is currently Safety Officer at the Department of Physics, University of Cambridge.

Autoren/Hrsg.

Blunt, J.

Balchin, N C

Inhaltsverzeichnis

1;Front Cover
;1
2;Health and Safety in Welding and Allied Processes;4
3;Copyright Page
;5
4;Table of Contents;6
5;Introduction;8
6;Part 1: Risks and Principles for their Control;10
6.1;Chapter 1. Setting up the Workplace;12
6.1.1;The Workplace;13
6.1.2;Lighting;14
6.1.3;Housekeeping;16
6.1.4;Manual Handling;16
6.1.5;Electrical Hazards;17
6.1.6;Electric and Magnetic Fields;18
6.1.7;Training;19
6.2;Chapter 2. First Aid and Accident Reporting;20
6.2.1;UK Legislation;20
6.2.2;USA Legislation;20
6.2.3;General Advice;21
6.2.4;Electric Shock;21
6.2.5;Burns;22
6.2.6;Eye Injuries;22
6.2.7;Heat Exhaustion and Heat Stroke;23
6.2.8;Exposure to Harmful Gases and Fumes;23
6.2.9;Accident Reporting;24
6.3;Chapter 3. Fire;25
6.3.1;Combustible Materials;25
6.3.2;Air;26
6.3.3;Sources of Ignition;26
6.3.4;Legislative Framework;26
6.3.5;Prevention of Fire;27
6.3.6;Preventing the Spread of Fire;28
6.3.7;Fire Detection;30
6.3.8;Evacuation and Means of Escape;30
6.3.9;Extinguishing Fires;31
6.3.10;Fire Procedure;33
6.3.11;Maintenance of Fire Precautions;33
6.3.12;Fire Brigade;34
6.4;Chapter 4. Compressed and Liquefied Gases;35
6.4.1;Hazards;35
6.4.2;Common Gases used in Welding and Cutting;36
6.4.3;Identification of Cylinders;38
6.4.4;Manifolded Cylinders;39
6.4.5;Disposable Cylinders;40
6.4.6;Cylinder Stores;40
6.4.7;Bulk Storage;41
6.4.8;Transporting Cylinders;42
6.4.9;Cylinder Valves;44
6.4.10;Security;44
6.4.11;Regulators and Gauges;44
6.4.12;Planning for Emergencies;45
6.5;Chapter 5. Fume, Dust, Vapour and Gases;47
6.5.1;Particle Size and Behaviour;47
6.5.2;Health Effects of Inhaled Substances;49
6.5.3;By-products of Welding;50
6.5.4;Composition of Fume in Welding;54
6.5.5;Quantity of Fume;54
6.5.6;Coatings;55
6.5.7;Plastic Coatings;57
6.5.8;Asbestos;58
6.5.9;Exposure Limits;59
6.6;Chapter 6. Control of Exposure to Fume, Dust, Vapour and Gases;60
6.6.1;Air;60
6.6.2;Control of Exposure to Fume, etc;60
6.6.3;Substitution/Adjustment of Parameters;60
6.6.4;Factors in Planning Ventilation;61
6.6.5;General Recommendations for Fume Control;61
6.6.6;Methods for the Control of Exposure to Fume;63
6.6.7;Treatment of Extracted Air;70
6.6.8;Respiratory Protective Equipment;71
6.6.9;Quantifying the Fume Extraction;72
6.6.10;Calculating the Reduction in Fume Level Required;74
6.6.11;Maintenance of Equipment;75
6.6.12;Training the Welders;75
6.7;Chapter 7. Radiation;76
6.7.1;Non-ionising Radiation;76
6.7.2;Sources of Radiation;76
6.7.3;Health Effects;76
6.7.4;Protection from UV–Visible–IR Radiation;77
6.7.5;Ionising Radiation;79
6.7.6;Health Effects of Ionising Radiation;79
6.7.7;Quantifying Ionising Radiation;79
6.7.8;Radiation Generators;79
6.7.9;Radioactive Substances;80
6.7.10;Setting up a Facility;80
6.8;Chapter 8. Noise and Vibration;81
6.8.1;Noise;81
6.8.2;Hearing Mechanism;81
6.8.3;Legislative Requirements (UK);83
6.8.4;Legislative Requirements (USA);84
6.8.5;Hearing Protection;85
6.8.6;Vibration;85
6.8.7;Legislative Requirements;87
6.8.8;Mitigating Methods for Vibration;87
6.9;Chapter 9. Mechanical Hazards;89
6.9.1;Safe Platforms;89
6.9.2;Obstructions;89
6.9.3;Mechanical Lifting;89
6.9.4;Manipulators and Positioners;90
6.9.5;Wire Feed Units;90
6.9.6;Grinding;91
6.9.7;Robots;91
6.9.8;Eye Protection;94
6.9.9;Protective Clothing;95
7;Part 2: Processes;96
7.1;Chapter 10. Gas Welding, Cutting and Preheating;98
7.1.1;The Gas Flame;98
7.1.2;Key Hazards;100
7.1.3;Explosion and Fire;100
7.1.4;Unexpected Release of Pressure;106
7.1.5;Eye Injuries and Burns;106
7.1.6;Fume Risks;108
7.1.7;Accumulations of Gas;109
7.1.8;Working Procedures;110
7.1.9;Pre-use Equipment and Area Checks;111
7.1.10;Contingencies;112
7.1.11;Maintenance;114
7.2;Chapter 11. Arc Welding and Cutting;115
7.2.1;The Electric Arc;115
7.2.2;Consumable Electrode Processes;115
7.2.3;Non-consumable Electrode Processes;118
7.2.4;Cutting and Gouging Processes;119
7.2.5;Other Arc Processes;120
7.2.6;Key Hazards;121
7.2.7;Further Reading;141
7.3;Chapter 12. Plasma Arc Processes;142
7.3.1;Key Hazards;143
7.4;Chapter 13. Electroslag Welding (ESW);147
7.4.1;Key Hazards;147
7.5;Chapter 14. Resistance Welding;150
7.5.1;Hazards;150
7.6;Chapter 15. Thermit Welding;157
7.6.1;Key Hazards;158
7.7;Chapter 16. Electron Beam Welding;162
7.7.1;Key Hazards;163
7.8;Chapter 17. Friction Welding;169
7.9;Chapter 18. Laser Welding and Cutting;171
7.9.1;Key Hazards;171
7.10;Chapter 19. Brazing and Braze Welding;178
7.10.1;Brazing Processes;178
7.10.2;Fume from the Alloy;183
7.10.3;Fume from the Fluxes;186
7.10.4;Surface Preparation and Cleaning Procedures;187
7.10.5;Physical Hazards;188
7.11;Chapter 20. Soft Soldering;190
7.11.1;Processes;190
7.11.2;Key Hazards;192
7.12;Chapter 21. Thermal Spraying;199
7.12.1;Flame Spraying;199
7.12.2;Arc Spray;199
7.12.3;Plasma Spray;200
7.12.4;High Velocity Oxy-fuel Spraying (HVOF);200
7.12.5;Key Hazards of the Processes;201
7.13;Chapter 22. Welding and Flame Spraying Plastics;207
7.13.1;Welding Processes;207
7.13.2;Flame Spraying Plastics;212
7.13.3;Solvent Bonding and Solvent Adhesives;213
7.13.4;Fume Hazards;213
7.14;Chapter 23. Inspection and Testing;215
7.14.1;Radiography;215
7.14.2;Other Crack Detection Methods;220
7.14.3;Etches;222
7.15;Chapter 24. Welding in More Hazardous Environments;223
7.15.1;Permit to Work Systems;223
7.15.2;Vessels that are Contaminated by Flammable Materials;224
7.15.3;Confined Spaces;227
7.15.4;Situations of Increased Risk of Electric Shock;229
7.15.5;Environments Containing Substances Hazardous to Health;232
8;Part 3: Legislation and Appendices;234
8.1;Chapter 25. Legislation;236
8.1.1;United Kingdom;236
8.1.2;United States of America;244
9;Appendix A: Glossary of Terms;248
10;Appendix B: Risk Assessment for Arc Welding;251
11;Appendix C: Useful Addresses and Abbreviations;256
12;References;258
13;Index;266

Leseproben

1 Setting up the Workplace
In both the United Kingdom and the United States of America, there is a legislative framework that assigns a very large measure of responsibility to employers for the health and safety of their employees. The detailed approach is slightly different and readers need to familiarise themselves with the requirements. Where they have doubts, they should consult the enforcing authorities for advice: • The Health and Safety Executive (United Kingdom) • Occupational Safety and Health Administration (United States of America). The general requirements in the United Kingdom are laid down in the Health and Safety at Work, etc, Act, 1974,1 which places a duty on all employers to ensure as far as is reasonably practicable, the health, safety and welfare of all of their employees while they are at work. Many duties are also extended to those not in their employment but who may be affected by the employer’s undertaking. The Act enabled the making of Regulations, which contain detailed specific requirements, which employers are required to comply with. The basis upon which employers should act is one of risk assessment – where employers must analyse the risks associated with their work activities and implement measures to control those risks.2 Employees are required to cooperate with their employer’s efforts to meet the requirements of the Act and the Regulations. There are two useful websites where further information may be obtained, Her Majesty’s Stationery Office,3 where the full text of all Statutory Instruments published since 1987 is available to view and print, and the Health and Safety Executive,4 (HSE), where there is a great deal of advice and guidance. The general requirements in the United States of America are laid down in section 5 of the Occupational Safety and Health Act of 1970,5 which requires employers to furnish each of their employees with employment and a place of employment which are free from recognised hazards that cause or are likely to cause death or serious physical harm to those employees. The Act requires employers to comply with the occupational safety and health standards that it promulgates. The Occupational Safety and Health Administration (OSHA) maintains a website from which access can be gained to Federal Regulations.6 Employees are required to comply with the rules, regulations and orders that apply to them. The net effect in both countries is that in order to ensure that the workforce remains safe and that the requirements are met, a system is needed to manage safety in the workplace. An efficient system will not only meet the legislative requirements, but is also cost effective in minimising lost time through illness and injury. The employer should set up a policy for the assurance of health and safety and assign responsibilities for undertaking the many tasks that will need to be carried out. The workplaces will need to be constructed and maintained in good order. The work equipment will need to be fit for its purpose and properly maintained .7 Setting up a safety committee enables worker participation and establishes good communication. Safety rules will be needed and the workforce will need to be trained so that they know what hazards they face, the preventive and protective measures that are needed to avoid the risk of injury or ill health, and how to make the best use of those measures, including personal protective equipment if it is needed.8 An inspection programme will be needed to ensure that the measures are adequate and that tasks are being carried out as required. In many workplaces, there will be a need for some health surveillance and monitoring of key indicators. The Workplace
First, the prescribed poster should be put up in the workplace. In the UK, this is available from the HSE or good bookshops.9 Alternatively, the prescribed leaflet10 may be distributed to every employee. In the USA, the prescribed poster11 can be downloaded from the government website. The workplace should be in accordance with the provisions of the Workplace Regulations,12 or in the USA, according to the requirements of subparts D and J of 29 CFR 1910.13,14 Indoor workplaces should be kept at a reasonable temperature. A temperature of 16 °C or above is recommended where personnel are undertaking light work, and a minimum of 13 °C where heavy work is undertaken. Measures may need to be taken in hot weather to prevent people from becoming overheated. Adequate sanitary facilities should be provided, with facilities for washing and drying the hands. The facilities should be kept clean. An area should be set aside, separate from the work area, where food and drink can be consumed without contamination by substances hazardous to health. Walkways should be marked and kept clear. The walkways should have surfaces that are free from holes, slippery substances and water, to avoid slips, trips and falls. There should be railings or other guards to prevent people from falling down stairs, shafts, etc. Lighting
When work must be carried out in areas where insufficient daylight is available it will be necessary to provide artificial lighting, which will almost invariably be electric. Two cases must be covered: normal operation and emergency lighting. General advice is given in an HSE publication.15 Normal lighting
The information in Table 1.1 below has been selected from Table 1 of the now obsolescent British Standard16 as that most likely to be applicable to welding activities. Table 1.1 Illuminances and corresponding activities 500 Moderately difficult Moderate Low 750 Difficult Small Low 1000 Very difficult Very small Very low 1500 Extremely difficult Extremely small Very low The general run of welding work on mild steel plate, often with a black surface, will be of very low contrast. Although arc welding is an almost unique operation, in that the arc emits far more light than any practicable artificial illumination, good general illumination will permit the use of a lighter shade of viewing filters because the eyes adapt to the general level of illumination by narrowing of the pupils and the arc light has to be reduced less to match. This gives welders a better view of the weld with less eye strain and renders them less susceptible to dazzle by an accidental view of an arc. Good lighting is also important to facilitate preparatory work, such as edge preparation and assembly of components, and visual checks after welding by the welder himself, etc. Where there is rotating machinery (such as turntables for spraying, or lathes) the designer of the lighting system should avoid stroboscopic effects. The environment in a normal welding shop will require allowance for reduction of output due to dust accumulation on luminaires (lighting fittings) during the intervals between routine lamp replacement and cleaning. It is not necessary to paint a welding shop black to avoid reflection of ultraviolet (UV) light (see Chapter 7). For work on site, some welding generators are available with an outlet to power lights; as this is often of low power or of non-standard voltage or frequency, the exact facilities required should be checked against the specification. For the illumination of fuel gas stores, where a leak could give rise to an explosive atmosphere, flameproof equipment will be required (see Chapter 4), unless it is possible to site the lighting outside the hazard area. This may offer security advantages. Emergency lighting
If a complete electrical power supply failure occurs after dark, emergency lighting will be needed to ensure that workers are able to see well enough to carry out such actions as the following: 1 Making safe any radiographic equipment, especially isotope sources, 2 Shutting down all gas flames for welding cutting preheating, etc, 3 Switching off all electric welding equipment, 4 Rendering safe any equipment relying on supplies also cut off by an electric power failure, such as water cooling, compressed air or ventilation systems, 5 Ensuring that all crane motors are switched off and that any suspended loads which present a hazard, will be marked if necessary, 6 Rescuing anyone trapped, such as in a crane jib or lift, 7 Evacuating the premises in an orderly fashion, making sure that no one is left behind. If it is necessary to cut off the supply in the event of fire, similar considerations will apply. Escape lighting should: 1 Indicate the escape routes clearly and unambiguously 2 Illuminate those routes that allow safe exit 3 Enable the ready location of fire alarm call points and fire fighting equipment on escape routes. On defined escape routes, 0.2 lux illumination is required and...