xviii Brazing Filler Metal ..........................448 Preparing to Braze or Braze Weld ....451 Brazing and Braze Welding Safety Precautions ..................................453 Brazing .............................................454 Braze Welding—Flat Position ..........456 Brazing and Braze Welding Out of Position.........................................460 Chapter 30 Soldering .....................................465 Soldering Principles .........................466 Advantages of Soldering ..................466 Soldering Filler Metals .....................466 Soldering Fluxes ..............................468 Hazards of Solders and Fluxes Containing Lead ...........................469 Acceptable Solders for Drinking Water Systems .............................471 Preparing to Solder ..........................472 Soldering Safety Precautions ...........472 Procedures for Torch Soldering ........472 Section 7 Resistance Welding Chapter 31 Resistance Welding: Equipment and Supplies ...............................479 Principles of Resistance Spot Welding .........................................480 Welding Machines ...........................480 Safety ...............................................487 Chapter 32 Resistance Welding: Procedures .491 Selecting the Welding Machine ........492 Setting the Welding Variables ..........492 Welding Mild Steel ...........................496 Welding Aluminum ...........................497 Projection Welding ...........................498 Resistance Seam Welding ...............499 Section 8 Welding in Industry Chapter 33 Pipe and Tube Welding ...............503 Pipes and Tubes ..............................504 Welding Processes ..........................506 Types of Joints .................................508 Pipe or Tube Welding Positions ........508 Preparations for Welding ..................509 SMAW of Pipe and Tube ..................512 GTAW of Pipe and Tube ...................519 GMAW and FCAW of Pipe and Tube .......................................520 Chapter 34 Robotics in Welding ....................525 The Reason for Robots ....................526 Types of Industrial Robots ...............526 Robotic Welding Systems ................527 Safety around Robots ......................531 Chapter 35 Special Welding and Cutting Processes ...................................537 Frequently Used Special Processes ...538 Special Arc Welding Processes ........538 Solid-State Welding Processes ........542 Other Welding Processes ................545 Special Cutting Processes ...............548 Chapter 36 Inspecting and Testing Welds ......553 Reasons for Inspecting Welds .........554 Types of Tests ..................................554 Chapter 37 Welder Certification .....................573 Codes and Specifications ................574 Employment Considerations ............579 Labor Unions ...................................579 Work Orders .....................................580