Oxyfuel Welding Equipment Chapter 12

Objectives Identify the various components of an oxyfuel gas welding outfit. Describe the function of each component of an gas welding out fit. Cite the maximum safe working pressure used for acetylene. List all the safety equipment that should be worn and used when oxyfuel gas welding in various positions.

Complete Oxyfuel Outfit Gas Supply Regulators Hoses Welding Torch Eye Protection Striker

Oxygen Supply Stored in high pressure cylinders Obtained By 2000-2640 PSI Obtained By Atmosphere Electrolysis Oxygen-bearing pellet

Oxygen Cylinders Interstate Commerce Commission (ICC) Forged in one piece Must be at least ¼ inch thick High carbon steel

Cylinder Valves Made of brass “Back-seating valve” Never use in the partly opened position Integrated pressure safety device Cylinder safety cap

Acetylene Cylinders Acetylene is not safe above 15 PSI Cylinders are filled with monolithic filler 85% porosity Charged with acetone Absorbs acetylene Fuse plugs

Pressure Regulators Reduce high cylinder pressure to working pressure Maintain a constant working pressure

Pressure Gauges Usually two on each regulator One indicates bottle pressure One indicates hose pressure

Hoses Hose colors Green and Black Red Red, green, and black Oxygen Acetylene

Torch Types Positive pressure type Injector type

Positive Pressure Type Mixing chamber is located inside the valve body Requires high pressure to mix gases

Injector Type Acetylene is injected into the oxygen stream using venturi action Mixing chamber creates turbulence to further mix gases

Welding Tips Solid copper Two different types of tips Do not drop tips One piece Two piece Do not drop tips Do not try to remove hot tips

Tip Cleaners Orifice size and shape must be maintained Splatter from base metal may contaminate tip Tip cleaners use a round file type cleaner Only correct size cleaners should be used Tips should be filed off perpendicular to orifice

Welding Eye Protection The shade used should be dark enough to protect the eyes from annoying glare; yet light enough to permit the welder to see his work .

Manual Metal Arc: 1/16, 3/32, 1/8, 5/32 inch electrodes 10 3/16, 7/32, 1/4 inch electrodes 12 5/16, 3/8 inch electrodes 14 MIG Welding (nonferrous) 11 MIG Welding (ferrous) 12 Atomic Hydrogen Welding 10-14 TIG Welding 12 Plasma Cutting 14 Carbon Arc 14 Torch Brazing 3 or 4 Light Cutting, up to 1 inch 3 or 4 Medium Cutting, up to 1 inch 4 or 5 Heavy Cutting, 6 inches and over 5 or 6 Gas Welding (Light) up to 1/8 inch 4 or 5 Gas Welding (Medium) 1/8 to 1/2 inch 5 or 6 Gas Welding (Heavy) 1/2 inch and over 6 or 8

Other Fuel Gases Hydrogen LP gas Natural gas Methylacetylene propadiene (MAPP)

Check Valves Only allows gas to flow in one direction Can be at torch inlet regulator outlet or both

Flashback Arrestors Check valve Pressure-sensitive cut off valve Stainless steel filter Heat-sensitive check valve