2 Objectives Describe oxy-fuel cutting principles. Identify oxy-fuel cutting equipment.Explain the safety issues of oxy-fuel cutting.Describe various support equipment for oxy-fuel cutting.Identify various cutting techniques.Describe the oxygen lance cutting process.
4 Oxyacetylene and Other Fuel Gas Cutting Limited to cutting ferrous materialsFerrous materials have affinity for oxygenRusting process is slow form of oxygen cuttingChemical cutting processArc or water jet processStainless steel, manganese steels and nonferrous materialsMechanical method of cutting
5 Oxygen CuttingRequires that the part to be cut be raised to a temperature of 1,500-1,600ºFStream of pure oxygen directed onto hot metal causing it to burn rapidlyBurning steel gives off iron oxide as a product of combustionIron oxide solid at room temperatureMelting point below melting point of steel so iron oxide runs off as molten slag, exposing more iron to jet
6 Properties of Common Fuel Gases Methylacetylene-propadiene (MPS)PropaneNaturalGasAcetylenePropyleneChemical formula C2H2 C8H8 C3H C3H4 CH4Neutral flame Fº 5, , , ,200 4,600Primary flame heat emission Btu/ftSecondary flameBtu/ft , , ,Look for the rest in Table 6.1 from text
7 Oxy-fuel Gas Cutting Equipment Single-purpose cutting torch, or welding torch to which adaptable cutting head is attachedFlint lighterOxygen regulatorAcetylene regulatorOxygen welding hose with couplings attached to each endAcetylene welding hose with couplings attached to each endFlame arresters and check valves
18 Orifice SizeCutting Oxygen orifice size not usually affected by type of fuel gas usedPreheat orifices need to be of appropriate design for type of fuel gas being used.Various fuel gases require different volumes of oxygen and fuelTips used for acetylene usually one piece, while other fuel cases may be one-or two-piece tips
34 Beam Cutter Two permanent magnets lock and square rail in position. Variable speed power units used on both horizontal and vertical drivesSquaring gauge enables operator to adjust tip quickly from bevel to straight trim cutsWeighs only 60 pounds so one operator setup times is minimalClean, accurate cuts done in minimum time