[Illustration: Figure 39.--Oxidizing Flame--Too Much Oxygen]
[Illustration: Figure 40.--Neutral Flame]
[Illustration: Figure 41.--Reducing Flame--Showing an Excess of Acetylene]
While welding, test the correctness of the flame adjustment occasionally by
turning on more acetylene or by turning off some oxygen until two flames or
cones appear. Then regulate as before to secure the single distinct cone.
Too much oxygen is not usually so harmful as too much acetylene, except
with aluminum. (See Figure 41.) An excessive amount of sparks coming from
the weld denotes that there is too much oxygen in the flame. Should the
opening in the tip become partly clogged, it will be difficult to secure a
neutral flame and the tip should be cleaned with a brass or copper
wire--never with iron or steel tools or wire of any kind. While the torch
is doing its work, the tip may become excessively hot due to the heat
radiated from the molten metal. The tip may be cooled by turning off the
acetylene and dipping in water with a slight flow of oxygen through the
nozzle to prevent water finding its way into the mixing chamber.
The regulators for cutting are similar to those for welding, except that
higher pressures may be handled, and they are fitted with gauges reading up
to 200 or 250 pounds pressure.
In welding metals which conduct the heat very rapidly it is necessary to
use a much larger nozzle and flame than for metals which have not this
property.
Pages:
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124