2 Objectives Understand facts about oxygen and acetylene Explain functions of oxyacetylene heatList the procedures for assembly of the oxyacetylene rigIdentify oxyacetylene equipment
3 Objectives Discuss safety precautions for oxyacetylene process Describe the procedures for turning on/off the oxyacetylene rig
4 Terms and DefinitionsPenetration: Distance from the original surface of the base metal to that depth at which fusion stops.Good or Bad Penetration?
5 Terms and DefinitionsBackfire: A short pop of the torch flame followed by extinguishing of the flame or continued burning of the gases.Flashback: when the torch flame moves into or beyond the mixing chamber.
6 Terms and DefinitionsTack Weld: A short weld used to hold work pieces togetherPreheating: Heating prior to a welding or cutting operation
7 Benefits of Learning Oxy-Acetylene welding and cutting Teaches methods used in forming and controlling a weld puddleTeaches methods of using welding equipment and techniques that are useful in other welding processes
8 Benefits of Learning Oxy-Acetylene welding and cutting Provides practice leading to good hand-eye coordinationFUN
9 Equipment requiredOxygen cylinder - filled with 2200 psi of pure compressed oxygenAcetylene cylinder – filled with 250 psi of compressed acetylenePressure regulators- regulate the gas and oxygen pressure
10 Equipment required Two hoses encased together green hose = oxygen red hose = acetyleneWelding torch with tipsWelding goggles and safety glassesshade 4-6 for oxy-fuel welding and cuttingZ87 safety glasses
11 Equipment required Striker- used to light initial flame Check valves- to prevent flashback
12 Safety Rules for Oxy-Acetylene Workplace Keep work area free of grease, oil, and flammable materialsCool or quench hot metal and extinguish all sparks before leaving
13 Safety Rules for Oxy-Acetylene Workplace Don’t leave torches, tips or hot metal where someone will pick them upNever carry matches or lighters into any work area
14 Personal Protective Equipment (PPE) ShirtsKeep collar and sleeves buttoned to keep out sparks and remove pockets or tape them shut
15 PPEPantsno cuffs or tears and come over shoe tops
16 PPE Shoes leather, cover entire foot Gloves Leather, never use to pick up metal (must not have holes in the finger tips)
17 PPESafety Glassesworn under helmets and goggles (Z87)
18 PPE Wear safety glasses at all times Wear welding goggles or a face shield with a lens no. 4-6when in doubt, start with a dark lens and then switch to a lighter one.
19 Pressure Regulating Valves Each regulator has two gauges mounted on a single manifold, one indicates cylinder pressure and the other indicates working pressure for the torchCylinder GaugeHose Gauge
20 Pressure Regulating Valves Each regulator has an adjusting screw so pressure to the torch can be quickly controlled by turning the screw righty-tighty increases pressure, left-loosey decreases pressure
22 Welding hoses Connecting threads acetylene connectors have a V-groove and left handed threads and oxygen connectors have plain surfaces and right handed threads
23 Parts of a welding torch Torch body is the part of the torch that is held like a pencil, it contains two needle valves to control flow of gasWelding head contains mixer, mixing throat, and the welding tip
24 Basic Safety Rules1. Before you start make sure personal safety is followed and PPE is worn2. Make sure you have had instruction3. Release adjusting screw on regulators before opening valves
25 Basic Safety Rules4. Stand on the opposite side of the regulator when opening a valve5. Open cylinder valve slowly, oxygen first and then acetylene just a quarter of a turn
26 Basic Safety Rules6. Do not use or compress acetylene at pressure higher than 15 psi or oxygen at a pressure higher then 40 psi.7. Set working pressures as desired.8. Light acetylene first, shut it off first
27 Basic Safety Rules9. Never use oil on regulators or any oxy-fuel equipment10. Do not use oxygen as a substitute for compressed air11. Keep heat, flames and sparks away from combustibles.
28 Basic Safety Rules12. Keep hoses out of sparks or spatter to prevent leaks13. To check for leaks use only soapy water
29 Types of Flames Oxidizing Excess oxygen with no feather, makes hissing sound
30 Types of Flames Neutral burns equal amounts of oxygen and acetylene and has a clear edged inner conemost commonly used
31 Types of Flames Carburizing Excess acetylene with an acetylene feather two to three times the length of the inner coneUsed some in hardsurfacing, adds carbon to metal
32 Safely lighting a flame Check the torch valves to make sure they are closedOpen the oxygen cylinder valve full open
33 Safely lighting a flame Open the acetylene cylinder 1/3 turnOpen the oxygen torch valve to get proper working pressure
34 Safely lighting a flame Close oxygen torch valveOpen the acetylene torch valve and set the proper working pressure
35 Safely lighting a flame Close the torch valveOpen the acetylene torch valve one and 1/2 of a turn
36 Safely lighting a flame Point the torch awayCrack acetylene valveStrike a spark to ignite
37 Safely lighting a flame Open the valve until it jumps off the tipClose the valve slightly to bring the flame back to the tipOpen the oxygen valve until a neutral flame is reached
38 Guidelines for Flame adjustment To get a neutral flame, always start with more acetylene, then increase oxygen until the acetylene feather disappears from the center coneExcess oxygen causes molten metal to spark
39 Guidelines for Flame adjustment Make sure regulators are set for the pressures recommended for the tip size
40 Shutting down the unit Close the acetylene valve Close the oxygen valveShut off the tanksOpen the acetylene to purge the line and then the oxygen
41 Shutting down the unit When both gauges read zero, close the valve Open the oxygen valve
42 Shutting down the unit When both gauges read zero, close the valve Release pressure by turning adjusting screw left (out)Coil hoses and put tools away and properly store the unit
43 Review What are the parts of oxy-fuel equipment? What are three safety precautions used when oxy-fuel welding?How do you safely operate the oxy-fuel equipment?