1、STD-AWS SP-ENGL 1788 07842b5 0537303 q8 SAFE PRACTICES Reprinted from the Welding Handbook Volume 1 ,Eighth Edition American Welding Society STD*AWS SP-ENGL 1988 m 078qZb5 0517301r 315 m Keywords-Safety , welding, fire, noise, fume, gases, electrical, training, equipment, practices Safe Practices Re
2、printed from the Welding Handbook, Volume 1, 8th Edition Prepared by Task Group of the Committee on Labeling and Safe Practices Issued 1988 Abstract This document covers the basic elements of safety applicable to all welding, cutting, and related processes. Sub- jects such as fumes and gases, precau
3、tionary labeling, handling of compressed gases, and electrical safety, in addition to hazards that are unique to particular welding or cutting processes, are addressed. A supplementary reading list is included. American Welding Society 550 N.W. LeJeune Road, P.O. Box 351040, Miami, FL 33135 STDOAWS
4、SP-ENGL 1988 07842b5 0517305 251 Personnel Welding Handbook Committee May 31, 1986 I. H. Hunnahs, Chairman M. J. Tomsic, Vice Chairman i P. Connor, Secretary D.R. Amos C. W. Case .R. Condru E. H. Daggett * * A.F. Mant J. C. Pupritun L. Privoznik D.R. Spisiuk Midmark Corporation Plastronics incorpora
5、ted American Welding Society Westinghouse Electric Corporation Inco Alloys International E. duPont de Nemours and Company Babcock and Wilcox A.F. Manz and Associates Ohio State University Westinghouse Electric Corporation Gaymar industries Incorporated Safety and Health Committee K.L. Brown, Chairma
6、n K.A. Lyttle, Ist V. Chairman . J. Simonton, 2nd V. Chairman M.E. Kennebeck, Jr., Secretary W. Cheney O. j. Fisher“ E.G. Hornberger D. G. Howden W.S. Howes A.F. Manz G. R. Spies, Y. * D. R. Wilson Lincoln Electric Company Union Carbide Corporation Inco Alloys international, Inc. American Welding So
7、ciety United Air Specialists Consultant Welding especially not those involving sophisticated technology. For this reason, those chapters in the handbook devoted to specific proceses should also be referenced for additional important safety information. Safety is an important consideration in all wel
8、ding, cutting, and related work. No activity is satisfactorily completed if someone is injured. The hazards that may be encountered and the practices that will minimize per- sonal injury and property damage are discussed here. MANAGEMENT SUPPORT THE MOST IMPORTANT component of an effective safety an
9、d health program is management support and direc- tion. Management must clearly state objectives and demonstrate its commitment to safety and health by con- sistent execution of safe practices. Management must designate approved areas where welding and cutting operations may be carried on safely. Wh
10、en these operations must be done in other than desig- nated areas, management must assure that proper proce- dures to protect personnel and property are established and followed. Management must be certain that only approved welding, cutting, and allied equipment is used. Such equipment includes tor
11、ches, regulators, welding machines, electrode holders, and personal protective devices. Adequate supervision must be provided to assure that all equipment is properly used and maintained. TRAINING THOROUGH AND EFFECTIVE training is a key aspect of a safety program. Adequate training is mandated unde
12、r provisions of the U.S. Occupational Safety and Health Act (OSHA), especially those of the Hazard Communi- cation Standard (29 CFR 1910.1200). Welders and other equipment operators perform most safely when they are properly trained in the subject. I Proper training includes instruction in the safe
13、use of equipment and processes, and the safety rules that must be followed. Personnel need to know and understand the rules and the consequences of disobeying them. For example, welders must be trained to position themselves while welding or cutting so that their heads are not in the gases or fume p
14、lume.2 Before work begins, users must always read and understand the manufacturers instructions on safe prac- tices for the materials and equipment, and also the mate- rial safety data sheets. Certain AWS specifications call for precautionary labels on consumables and equipment. These labels con- ce
15、rning the safe use of the products should be read and followed. A typical label is illustrated in Figure 1. Manufacturers of welding consumables must provide on request a Material Safety Data Sheet (MSDS) that identifies those materials present in their products that have hazardous physical or healt
16、h properties. The 1. The term welder is intended to include all welding and cutting per- sonnel, brazers, and solderers. 2. Fume plume is the smoke-like cloud containing minute solid parti- cles arising directly from the area of melting metal. in distinction to a gas, fumes are metallic vapors that
17、have condensed to solid and are often associated with a chemical reaction, such as oxidation. STD-AWS SP-ENGL 1988 D 078q2b5 0517322 555 9 2 WARNING: PROTECT yourself and others. Read and understand this label. FUMES AND GASES can be dangerous to your health. ARC RAYS can injure eyes and burn. ELECT
18、RIC SHOCK can KILL. Read and understand the manufacturers instructions and your employers safety practices. Keep your head out of the fumes. Use enough ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and the general area. Wear correct eye, ear, and body pro
19、tection. Do not touch live electrical parts. See American National Standard 249.1 “Safety in Welding and Cut- ting” published by the American Welding Society, 550 N.W. LeJeune Rd., P.O. Box 351040, Miami, Florida 33135; OSHA Safety and Health Standards, 29 CFR 1910, available from U.S. Government Pr
20、inting Office, Washington, DC 20402. DO NOT REMOVE THIS LABEL Figure 1-Minimum Warning Label for An: Welding Processes and Equii MSDS provides the OSHA Permissible Exposure Limit (PEL), and any other exposurelimit used or recom- mended by the manufacturer. Employers that use consumables must make th
21、e appli- cable MSDS readily available to their employees, as well as train them to read and understand the contents. The MSDS contain important information about the ingredi- ents contained in welding electrodes, rods, and fluxes, the composition of fumes which may be generated in their use, and mea
22、ns to be followed to protect the welder and others from hazards which might be involved. Under OSHA Hazard Communication Standard 29 CFR 1910.1200, employers are responsible for the training of employees with respect to hazardous materi- als used in their workplace. Many welding consumables are incl
23、uded in the definition of hazardous materials according to this standard. Welding employers must comply with the communication and training require- ments of this standard. * The proper use and maintenance of the equipment must also be taught. For example, defective or worn electrical insulation can
24、not be tolerated in arc welding or cutting, nor can defective or worn hoses be used in oxyfuel gas welding and cutting, brazing, or soldering. Proper training in equipment operation is fundamental to safe operation. Persons must be trained to recognize safety hazards. If they are to work in an unfam
25、iliar situation or environ- ment, they must be thoroughly briefed on the potential hazards involved. For example, consider a person who must work in a confined space. If the ventilation is poor and an air-supplied helmet is required, the need and instructions for its proper use must be thoroughly ex
26、plained to the employee. The consequences of improperly using the equipment must be covered. When employees believe that the safety precautions for a given task are not adequate, or not understood, they should question their supervisors before proceeding. GENERAL HOUSEKEEPING GOOD HOUSEKEEPMG IS ess
27、ential to avoid injuries. A welders vision is often restricted by necessary eye pro- tection. Persons passing a welding station must shield their eyes from the flame or arc radiation. The limited vision of the welder and passers-by makes them vulnera- ble to tripping over objects on the floor. There
28、fore, STD*AWS SP-ENGL 3788 welders and supervisors must always make sure that the area is clear of tripping hazards. Management must lay out the production area so that gas hoses, cables, mechanical assemblies, and other equipment do not cross walkways or interfere with routine tasks. When work is a
29、bove ground or ffoor level, safety rails or lines must be provided to prevent falls as a result of restricted vision from eye protection devices. Safety lines and harnesses can be helpful to restrict workers to safe areas, and to catch them in case of a fail. Unexpected events, such as fire and expl
30、osions, do occur in industrial environments. All escape routes must be identified and kept clear so that orderly, rapid, and safe evacuation of an area can take place. Storage of goods and equipment in evacuation routes should be avoided. If an evacuation route must be temporarily blocked, employees
31、 who would normally use that route must be trained .to use an alternate route. PROTECTION IN THE GENERAL AREA EQUIPMENT, MACHINES, CABLES, hoses, and other appa- ratus should always be placed so that they do not present 078q2b5 0537332 i73 3 a hazard to personnel in passageways, on ladders, or on st
32、airways. Warning signs should be posted to designate welding areas, and to specify that eye protection must be worn. Rotective Screens PERSONS IN AREAS adjacent to welding and cutting must be protected from radiant energy and hot spatter by (1) flame-resistant screens or shields, or (2) suitable eye
33、 and face protection and protective clothing. Appropriate radiation-protective, semi-transparent materials are permissible. Where operations permit, work stations should be separated by noncombustible screens or shields, as shown in Figure 2. Booths and screens should permit cir- culation of air at
34、floor level as well as above the screen. Wall RefkWy WHERE ARC WELDING or cutting is regularly carried on adjacent to painted walls, the walls should be painted STD.AWS SP-ENGL LWA m OWIZU 0517313 328 m 4 with a finish having low reflectivity of ultraviolet radia- tin. Finishes formulated with certa
35、in pigments, such as titanium dioxide or zinc oxide, have low reflectivity to ultraviolet radiation. Color pigments may be added if they do not increase reflectivity. Pigments based on pow- dered or flaked metals are not recommended because they reflect ultraviolet radiation. PUBLIC DEMONSTRATIONS P
36、ERSONS PUTTING ON public demonstrations involving observation of arc or oxyfuel gas welding or cutting pro- cesses are responsible for the safety of observers and the general public. Observers are not likely to have the nec- essary protective equipment to let them observe demon- strations safely. Fo
37、r exhibits involving observation of arc or oxyfuel gas welding and cutting processes, appro- priate eye protection for both observers and passers-by is mandatory. Fume exposure must be controlled by appropriate ventilation. Electric cables and hoses must be routed to avoid audience exposure to possi
38、ble electric shock or tripping hazards. Protection must be provided against fires from fuels, combustibles, and overheated appara- tus and wiring. Fire extinguishers must be on hand in case of fire. Combustible materials must be removed from the area or shielded from flames, sparks, and molten metal
39、. Safety precautions at public events should be passive types, that is, they should not require the audience to take action to protect itself. For example, a protective, moveable transparent screen allows an audience to observe a welding operation with the screen in place. After welding is completed
40、, the screen can be moved to allow the audience to observe the completed weld. Addi- tional information is given in ANSI/ASC 249.1, Safety in Welding and Cutting. FIRE IN MOST WELDING, cutting, and allied processes, a high- temperature heat source is present. Open flames, electric arcs, hot metal, s
41、parks, and spatter are ready sources of ignition. Many fires are started by sparks, which can travel horizontally up to 35 feet from their source and fall much greater distances. Sparks can pass through or lodge in cracks, holes, and other small openings in floors and walls. The risk of fire is incr
42、eased by combustibles in the work area, or by welding or cutting too dose to combus- tibles that have not been shielded. Materials most com- monly ignited are combustible floors, roofs, pamtions, and building contents induding trash, wood, paper, tex- 3. For further guidance, see Ultraviolet Reflect
43、ance of Paint. Miami:American Welding Society, 1976. tiles, plastics, chemicals, and flammable liquids and gases. Outdoors, the most common combustibles are dry grass and brush. The best protection against fire is to perform welding and cutting in specially designated areas or enclosures of noncombu
44、stible construction that are kept free of com- bustibles. Combustibles should always be removed from the work area or shielded from the operation. Fuel for engine driven equipment should be stored and used with care. Equipment manufacturers instructions should be followed because fuels and their vap
45、ors are combustible and can be explosive under some conditions. Fuel gases, such as acetylene or propane, are other common flammables often found in cutting and welding areas. Special attention should be given to fuel gas cylin- ders, hoses, and apparatus to prevent gas leakage. Combustibles that ca
46、nnot be removed from the area should be covered with tight fitting, flame resistant material. These include combustible walls and ceilings. Floors should be free of combustible materials for a radius of 35 feet around the work area. All doorways, windows, cracks, and other openings should be covered
47、 with a flame-resistant material or, if possible, the work area should be enclosed with portable flame-resistant screens. if welding or cutting is to be performed on or adjacent to a metal wall, ceiling, or partition, combustibles on the other side must be moved to a safe location. If this can- not
48、be done, a fire watcher should be stationed where the combustibles are located. Heat from welding can be conducted through metal partitions and ignite combus- tibles on the opposite side. A thorough examination for evidence of fire should be made before leaving the work area. Fire inspection should
49、be continued for at least 30 minutes after the operation is completed. Welding or cutting should not be performed on mate- rial having a combustible coating or internal structure, as in walls or ceilings. Hot scrap or slag must not be placed in containers holding combustible materials. Suitable fire extinguishers should always be available nearby. Welding, brazing, or cutting should not be performed on combustible floors or platforms that may readily be ignited by heat from the operation. Welders must be alert for traveling vapors of flammable liquids. Vapors are often heav
