AWS C7.3 pdf free download

AWS C7.3 pdf free download.Process Specification for Electron Beam Welding.
3. Terms and Definitions AWS A3.0M/A3.0, Standard Welding Terms and Definitions Including Terms for Adhesive Bonding, Brazing, Soldering, Thermal Cutting, and Thermal Spraying, provides the basis for terminology used herein. reference document. A type of document that outlines procedures as they relate to a particular activity. A reference document outlines the procedures undertaken during an activity to avoid missing steps the next time that the activity is performed. 4. Safety These safe practice recommendations are abstracted from AWS C7.1. That document and the manufacturer’s manuals should be consulted for a more complete treatment of the subject. Some of the following potential hazards of Electron Beam Welding are above and beyond those traditionally associated with other welding processes. 4.1 Electric Shock. The typical primary voltage to an electron beam welding machine is 440 volts AC. That voltage is stepped up to several thousand volts for the electron beam gun and also for the vacuum (ionization) gauge(s). These voltages, and their associated currents, can be lethal. 4.1.1 All doors and access panels on electron beam welding equipment shall be properly secured and interlocked to prevent accidental or unauthorized access.
4.1.2 All conductors shall be fully enclosed by grounded, conductive barriers that are also interlocked. 4.1.3 A grounding probe must be used before servicing the electron beam gun and high voltage power supply. 4.1.4 Appropriate warning signs shall be affixed to the equipment per ANSI Z49.1. 4.1.5 Follow appropriate lock-out and tag-out procedures when servicing electron beam equipment. 4.2 Materials, Fumes, and Gases. Harmful gases and vapors may be generated during electron beam welding. 4.2.1 Exhaust venting and filtering shall be provided for vacuum processing. 4.2.2 Hazardous levels of cleaning solution and solvent vapors shall be avoided/prevented when cleaning the vacuum chamber for high vacuum processing. 4.2.3 Safety Data Sheets (SDS) shall be read by Welding Operator Maintenance personnel and all those involved in the maintenance process to determine hazards in working with all materials associated with the welding process. SDS shall be followed. These include the SDS for all cleaning solvents, materials contained in the workpiece, and fixturing. 4.3 X-Radiation. X-radiation is produced by electron beam welding equipment during operation. The system design incorporates shielding which reduces the radiation to allowable levels.
4.3.1 Proper shielding shall be employed to protect personnel from X-ray leakage. 4.3.2 Equipment shall be inspected and a radiation survey shall be conducted periodically to ensure that shielding is performing properly, as specified by the machine manufacturer. 4.3.3 All users of the equipment shall establish and adhere to a radiation safety program. 4.4 Visible Radiation. Direct viewing of the weld area during welding can expose personnel to visible, infrared, and ultraviolet radiation. Appropriate optical filters shall be used per ANSI Z87.1 to shield personnel from visible and ultraviolet light exposure. 4.5 Vacuum. All electron beam welding machines covered by this document use vacuum pumping to protect the beam during transmission and to prevent degrading of the workpiece. The American Vacuum Society Vacuum Hazards Manual can be consulted for appropriate safety precautions when working with vacuum systems on electron beam welding equipment.AWS C7.3 pdf download.