AWS C7.1M-C7.1:2013 pdf download.Recommended Practices for Electron Beam Welding and Allied Processes
1.1 Scope. These recommended practices present descriptions of electron beam welding equipment and procedures for welding a wide range of metals and thicknesses; allied processes, to include electron beam braze welding (EBBW), cut-ting, drilling, surfacing, additive manufacturing, surface texturing, and heat treating, are also discussed. The appropriate terms, definitions, and safety considerations are presented. Information is included on designing for electron beam weld-ing (EBW), welding dissimilar metals and thicknesses, fixturing, specifications, and operator training and qualification.Information regarding the safe practice of electron beam welding and allied processes can be found in Clause 4 of this standard.
4. Safety Considerations
4.1 Scope. These safe practice recommendations are intended to provide a baseline for owners and users of electron beam welding equipment to enhance operator safety. This clause gives a set of minimum standards to observe in order to protect personnel and property from the potential hazards specifically associated with EBW. No attempt is made to include all the potential hazards associated with welding processes in general, which are covered by ANSI Z49.1, Safery in Welding, Cutting, and Allied Processes, nor all the OSHA regulations established to protect personnel working on (or around) various forms of industrial machinery and vacuum equipment. Additional safety information may be provided by the equipment manufacturer or integrator.
4.2.1 Electric Shock. The voltages employed in EBW machines are sufcient to cause fatal injury to personnel. All elec-trical equipment associated with EBW machines should be installed in accordance with the American National Standards Institute (ANSI) specification NFPA 70, National Electrical Code, with primary reference to Article 660; and in accor-dance with the National Fire Protection Association specification NFPA 79, Electrical Standard for Industrial Machinery.All doors and access panels on EBW equipment should be properly secured (electrically or mechanically) to prevent access by unauthorized persons to electrical components. All conductors operating at the accelerating potential shall be fully enclosed by grounded, conductive barriers that are interlocked to prevent access during operation. Before servicing the electron gun and high-voltage power supply components is permitted, a grounding probe shall be used to ensure complete discharge of all components. This grounding probe shall be left connected to the high-voltage terminal at all times when servicing the high-voltage power supply. Wherever access to high voltage is possible, the area should be properly posted in accordance with ANSI Z535.1, Safety Color Code, ANSI Z535.2, Environmental and Facility Safety Signs, and ANSI Z535.5, Accident Prevention Tags.AWS C7.1M-C7.1 pdf download.