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CONSULTANTS

OXY FUEL FLAME CUTTING

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CONSULTANTS

OXY FUEL FLAME CUTTING

•Cutting Gas

• Oxygen

•Fuel Gas

• Acetylene

• LPG – Liquid Petroleum Gas

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CONSULTANTS

OXY FUEL FLAME CUTTING

•Oxygen Gas

•Extracted From

- Atmosphere, Fractionalization Of Air

- Water, Electrolysis

•Stored In Cylinders

- At High Pressure – 1800 psi

- Cylinder Colour – Black

- Quantity in Volume 7.3 M3

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CONSULTANTS

OXY FUEL FLAME CUTTING

•Acetylene – Fuel Gas

• Produced by the reaction of

- Calcium Carbide with Water

- Cac2 + 2H2O = C2H2 + Ca(OH)2

• Molecular Weight – 26, Lighter Than Air

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CONSULTANTS

OXY FUEL FLAME CUTTING

•Acetylene – Fuel Gas

• Unsafe to Store Free Acetylene above 0.2 Kgs/cm2 – Decompose With Explosion

• Acetylene Dissolves in Acetone @ 25:1 (V/V) at 1 Atmospheric Pressure

• Solubility increases in multiples of 25 for every increase in Pressure by 1 atmospheric

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CONSULTANTS

OXY FUEL FLAME CUTTING

•Acetylene – Fuel Gas

• Stored In cylinders with Porous Mass- dissolved in Acetone

- Maximum Pressure of DA – 20 Kgs/cm2

- Quantity of DA Gas in Full cylinder By volume 6 – 7 M3

- Cost of Gas Appx. Rs:100/- per M3

- Purity of Gas Not Less Than 96%

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CONSULTANTS

OXY FUEL FLAME CUTTING

•Acetylene – Fuel Gas

• Cylinder Colour- Maroon

• Flat Bottom Cylinders – To be Kept Vertical While in Use

• Internal Bore of Cylinder neck - Left Hand Threaded

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CONSULTANTS

OXY FUEL FLAME CUTTING

• LPG – Fuel Gas• Produced in refineries • Stored In cylinders

- Liquid + vapor stage- At Low Pressure- Cylinder Colour- Red- Flat Bottom Cylinder- Quantity in Weight – 5 kg

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CONSULTANTS

OXY FUEL FLAME CUTTING

Type Of Oxy - Fuel Gas Flames

Carburising Flame

Neutral Flame

Oxidising Flame

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CONSULTANTS

OXY FUEL FLAME CUTTING

Cutting Process

• Feasible Only On Plain Carbon Steels & Low Alloy Steels

• Process is by Conversion of iron to iron oxide

• Steel Locally Heated to Kindling Temperature (800˚C) by Oxy Fuel Preheating Flame.

• A jet of oxygen is then impinged on this preheated hot iron.

• Iron instantaneously converted in to black iron oxide.

• Exothermic Reaction

• 2Fe + O2 = FeO + Heat (270 kJ),

• 3Fe + 2O2 = Fe3O4 + Heat (1100kJ)

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CONSULTANTS

OXY FUEL FLAME CUTTING

Cutting Process

• Kinetic energy of Oxygen jet drives all non metallic iron oxide .

• Heat Generated in exothermic reaction is self sustaining for preheating the metal ahead to cut

• When flame with a jet of oxygen at the centre moves close to the material, the process is continues by separating the material along the path of oxygen jet

• Purity of oxygen required for cutting - 99.5%

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CONSULTANTS

OXY FUEL FLAME CUTTING

Cutting Process

Typical Flame Cutting Nozzle

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CONSULTANTS

OXY FUEL FLAME CUTTING

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Cutting Blow Pipe / Torch

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CONSULTANTS

OXY FUEL FLAME CUTTING

ESAB make Cutogen Nozzles for Acetylene

Material ThicknessSize of Nozzle

Cutting Oxygen Pressure

mm inch Kg/cm2 lb./in2

6 1/4 1/32-A-8 1.4 20

12 1/2 3/64-A-12 2.0 30

25 1 1/16-A-16 2.5 35

50 2 1/16-A-16 3.2 45

75 3 1/16-A-16 3.5 50

100 4 1/16-A-16 4.2 60

150 6 5/64-A-20 4.5 65

200 8 3/32-A-24 4.9 70

250 10 7/64-A-28 5.3 75

300 12 1/8-A-32 5.3 75

Acetylene pr. should be set in all cases at 0.14 kg/cm2, 2 lb./in2.

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CONSULTANTS

OXY FUEL FLAME CUTTING

ESAB make LPG / NG nozzle

Thickness

Nozzle Size

Operating Pressure

Oxygen L.P.G/ N.G.

mm Kg/cm2 Kg/cm2

6 P-8 2.1 0.2

13 P-12 2.1 0.2

25 P-16 2.8 0.2

50 P-16 3.2 0.3

75 P-16 3.5 0.3

100 P-20 3.5 0.3

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Cutting Process Using• LPG as Fuel Gas

- Comparatively Poor Cutting Edge / Surface.- Maximum Cutting Thickness – 100 mm- Cutting Nozzle –Two Piece Construction- Cutting Parameters (Pressure - O2 & LPG & Cutting Speed) different from Oxy acetylene

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Cutting Process Using• Acetylene as Fuel Gas

- Comparatively Good / Smooth Cutting Edge / Surface.- Maximum Cutting Thickness – 300 mm- Cutting Nozzle –Single Piece Construction- Cutting Parameters (Pressure - O2 & C2H2 & Cutting Speed) different from Oxy + LPG

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Accessories- Gas Cylinders( O2 & Fuel Gas) with Pressure Regulators.- Pair of Hose Pipe Connections- Cutting Torch - Cutting Nozzle

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Accessories – O2 Cylinder- Oxygen Cylinder Neck – Right Hand Threaded

- All connections to O2 Gas Regulator, Hose Nipples , Torch Nipples- Right Hand Threaded

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Accessories – C2 H2

- Acetylene Cylinder Neck – Left Hand Threaded With A Notch on Hexagonal Nut

- All connections to Acetylene Gas Regulator, Hose Nipples , Torch Nipples- Left Hand Threaded

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Difference in Appearance of Accessories- Oxygen Cylinder – Black- Oxygen Cylinders may or may not be flat

bottom- Oxygen Gas Regulator, Hose, knob on Torch- Black - Hexagonal Nipple Connections of O2

Gas Without Any Notch – Plain

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CONSULTANTS

OXY FUEL FLAME CUTTING

• Difference in Appearance of Accessories- Acetylene Cylinder – Maroon - Acetylene Cylinder- Flat Bottom- Acetylene Gas Regulator, Hose , Knob on Torch – Maroon- Hexagonal Nipple Connections of Acetylene Gas - With Notch on Corners

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