The action is so fast
that metal is not injured on either side of the cut.
_Carbon Removal._--This process depends on the fact that carbon will
burn and almost completely vanish if the action is assisted with a supply
of pure oxygen gas. After the combustion is started with any convenient
flame, it continues as long as carbon remains in the path of the jet of
oxygen.
_Materials._--For the performance of the above operations we require
the two gases, oxygen and acetylene, to produce the flames; rods of metal
which may be added to the joints while molten in order to give the weld
sufficient strength and proper form, and various chemical powders, called
fluxes, which assist in the flow of metal and in doing away with many of
the impurities and other objectionable features.
_Instruments._--To control the combustion of the gases and add to the
convenience of the operator a number of accessories are required.
The pressure of the gases in their usual containers is much too high for
their proper use in the torch and we therefore need suitable valves which
allow the gas to escape from the containers when wanted, and other
specially designed valves which reduce the pressure. Hose, composed of
rubber and fabric, together with suitable connections, is used to carry the
gas to the torch.
The torches for welding and cutting form a class of highly developed
instruments of the greatest accuracy in manufacture, and must be thoroughly
understood by the welder.
Pages:
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37