Oxyfuel Cutting Chapter 14

Objectives Identify the various components of an oxyfuel cutting outfit. Cite the maximum safe working pressure used for acetylene gas.

Objectives Describe the function of each component of an gas cutting outfit. Correctly select the proper cutting tip and working pressure for a particular thickness of steel. Distinguish between a well cut surface and a poorly cut surface and be able to adjust where necessary to perform a good cut.

Cutting Torch

Oxygen control Velocity Oxygen pressure Amount of oxygen Orifice size

Torch movement Away from welder not toward No side to side is needed

Right to left or left to right? Right to left best for right-handed welders Whatever is most comfortable left to right best for left-handed welders

Cutting Angle Thin 1/8” or less Use a small tip Slant tip to 15-20° Thick Perpendicular both ways Use a larger tip

Slag Stream Less then 1” should go directly through Thicker then 1” some drag is desirable To ensure proper oxygen consumption

Drag The distance between the entry and exit point of the oxygen jet

Causes of Excessive Drag Incorrect flame adjustment Oxygen cutting pressure low Traveling too fast

Effect of Excessive Drag Not cutting completely through the metal Cerates turbulence and makes kerf rough

Bell-mouthed kerf Too much oxygen cerates a bell-mouthed kerf

Piercing Requires more heat Use 1 size larger tip Metal must be heated completely though

Cut Quality