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Welding Safety. How to stay alive!. What are some fuels that are around us?. Gasoline Diesel Kerosene Propane Acetylene Natural gas. Wood Coal Oil Corn Butane Ethanol. Which Fuel?.
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Welding Safety How to stay alive!
What are some fuels that are around us? • Gasoline • Diesel • Kerosene • Propane • Acetylene • Natural gas • Wood • Coal • Oil • Corn • Butane • Ethanol
Which Fuel? • The best way to determine which fuel to use is to consider its application or how it is going to be used.
Propane & Acetylene • These two fuels are different from other fuels because: • They are gases at normal atmospheric pressure. When they are compressed in a tank they become liquefied.
Parts of the Oxy-Acetylene rig • Acetylene side • Acetylene cylinder (tank) • Cylinder valve • One turn open • Cylinder pressure gauge • Regulator • Hose pressure gauge • Red hose • Acetylene valve on torch
Parts of the Oxy-Acetylene rig • Oxygen side • Oxygen cylinder (tank) • Cylinder valve • Open all the way • Cylinder pressure gauge • Regulator • Hose pressure gauge • Green hose • Oxygen valve on torch
Parts of the Oxy-Acetylene rig • Both have: • Torch mixing chamber • Torch tip • Uses for an oxy-acetylene torch • Cutting • Heating (rose bud) • Welding/brazing
Parts of the torch • Torch body
Parts of the torch • Valves
Parts of the torch • Mixing Chamber
Parts of the torch • Torch tip
Lighting Procedure • Check regulator thumb screws • Turn on oxy valve all the way • Set correct oxy working pressure • 25 – 30 psi • Open fuel valve half turn • Set correct fuel working pressure • 5 – 7 psi
Lighting Procedure • Light the flame • With what? • Shut down flame (fuel first) • Turn fuel cylinder valve off • Empty fuel hose • Turn oxy cylinder valve off • Empty oxy hose • Loosen regulator thumb screws
Oxygen • Hollow • Green • Open all the way (back seating valve) • 2300 psi • 25 – 30 Working psi • Larger than acetylene • Why?
Acetylene • Not Hollow • Acetone (liquid) • 300 – 350 psi • 5 – 7 Working psi • Explosive at 15 psi • 1/7 rule per hour • Smaller than oxygen
Oxygen • Colorless • Odorless • Promotes combustion • Not flammable
Acetylene • Colorless • Odor • Flammable • Unstable • Explosive over 15 psi
Regulators • There are two gauges on each regulator. One displays the tank pressure, and the other displays the working (hose) pressure.
Regulators • They are needed to: • Reduce tank pressure to working pressure, and • Keep that pressure constant
Arc Welding • SMAW • Shielded Metal Arc Welding • GMAW • Gas Metal Arc Welding • MIG - Metal Inert Gas • TIG - Tungsten Inert Gas • FCAW • Flux Core Arc Welding
More Hazards with Electricity • Shock • Fumes • UV Rays • Spark Spatter • Fire and Explosion
UV Ray protection • When using an electrical welder you should use a #10 shaded lens. • When welding with oxy-acetylene use #5 shaded lens
Polarity • AC - Alternating Current • DCS - Direct Current Straight • 70% of heat on steel • DCEN (electrode -) • DCR - Direct Current Reverse • 70% of heat on electrode • DCEP (electrode +)
Types of materials used for welding • Mild Steel • High Carbon • Special Alloy • Cast Iron • Nonferrous (Stainless Steel) • Hard facing and Buildup • Aluminum
Purpose of Flux • Easier to strike an arc • Floats impurities (contaminants) to the top • Cleans base metal • Forms slag • Keeps oxygen out of the weld • Improves weld appearance
What else do you need to know? • Throw away used rods 2” or less in the scrap bucket • To avoid welder damage or accidents • Warn people around you when striking an arc to prevent eye burns • “Cover!”
The number means something • Example: E6013 • E = electrode/electricity • 60 = 60,000 psi tensile strength • 1 = position: all • Flat, horizontal, vertical, overhead • 3 = welding current: AC and DC
Safety is #1 • Safety glasses • Helmet • Gloves • Protective clothing • Equipment instruction • Warning others • Distractions • Clean-up • Others
Class A • Ordinary combustibles • Wood and paper • Shape Triangle
Class B • Flammable liquids • Grease • Gasoline • Oil • Shape Square
Class C • Electrically energized fires • Shape Circle
Class D • Flammable metals • Specific for the type of metal • Shape Star