Nature of the Workpiece (Continued,
For example, MAPP gas does not operate at peak
on the same side as the torch. The alloyed or higher
carbon cladding does not bum as readily as the carbon
efficiency in most acetylene tips because the preheat
orifices are too small. If MAPP gas is used with a
steel.
natural-gas tip, the tip will overheat and become
By putting the cladding on the bottom, and the carbon
susceptible to flashback. In an emergency, a
natural-gas tip can be used with MAPP gas by
steel on the top, a cutting action similar to powder
cutting results. The low-carbon steel on top bums
removing its skirt. Similarly, an acetylene tip can be
readily and forms slag. As the iron-bearing slag passes
used if inefficient burning can be tolerated for a short
through the high-carbon or high-alloy cladding, it
run.
dilutes the cladding material. The torch, in essence,
Oxygen Supply
still bums a lower carbon steel. If the clad or
high-carbon steel is on the top surface, the torch is
required to cut material that is not readily oxidizable,
Oxygen supply means two things - volume and
and forms refractory slags that can stop the cutting
pressure. Both are needed to obtain a decent stinger to
provide a good quality cut. If all the oxygen volume in
action.
the world is available, and the pressure is low, the
oxygen system will be deficient. Also, very high
Tip Size and Style
oxygen pressures will not help when only a small
volume of oxygen is available over a given time.
All steel sections have corresponding tip sizes to allow
the most economical operation for a particular fuel.
It is as important to have a generous supply of oxygen
Any fuel will burn in any tip, of course, but not as
as it is to have well-trained burners, good equipment,
efficiently and may even overheat enough to melt the
and a quality fuel gas. Insufficient oxygen usually
tip or cause problems in the cut.
4-19