CHAPTER 8
OXYACETYLENE CUTTING AND WELDING
LEARNING OBJECTIVES
Upon completion of this chapter; you will be able to perform the following:
Describe the equipment used in oxyacetylene welding and the proper proce-
dures for setup and safe operation of the equipment.
State the principles of oxyacetylene cutting.
Identify the parts of a cutting torch and the function of each part, and describe
some of the special cutting techniques.
Identify the safety precautions you should follow when performing cutting
operations.
Describe the different techniques of oxyacetylene welding and the safety
precautions you should follow.
lengths of hose with fittings, a welding torch with tips,
INTRODUCTION
and either a cutting attachment or a separate cutting
This chapter deals with oxyacetylene cutting and
welding processes, and identifies the equipment and
torch, an apparatus wrench to fit the various
the operation of the equipment used in oxyacetylene
connections on the regulators, the cylinders, and the
operations.
torches; goggles with filter lenses for eye protection;
and gloves for protection of the hands. Flame-resistant
Oxyacetylene cutting is a method of cutting metal
clothing is worn when necessary.
by using heat and a jet of pure oxygen to produce a
chemical reaction known as oxidation. The results
The major components of a typical portable
obtained by using the oxyacetylene cutting method
oxyacetylene outfit are shown in figure 8-1. Figure 8-2
will range from a ragged, inaccurate edge to a smooth
illustrates a stationary acetylene cylinder bank of a
edge. The material being cut, the cutting method used,
type used at some activities.
and the skill of the operator are among the factors that
determine the final results.
ACETYLENE
Oxyacetylene welding is a nonpressure process in
Acetylene (chemical formula C2H2) is a fuel gas
which coalescence is produced by heat from an
made up of carbon and hydrogen. When burned with
oxyacetylene flame formed by the combustion of
oxygen, acetylene produces a very hot flame, having a
oxygen and acetylene. The two gases are mixed to
temperature between 5700F and 6300F. Acetylene
correct proportions in a torch. The torch can be
gas is colorless, but has a distinct, easily recognized
adjusted to give various types of flame.
odor. The acetylene used on board ship is taken from
compressed gas cylinders. The cylinder is filled with
balsa wood, charcoal, finely shredded asbestos, corn
OXYACETYLENE EQUIPMENT
pith, portland cement, or infusorial earth (an absorbent
material composed of decayed organic matter). These
Oxyacetylene equipment consists of a cylinder of
porous filler materials are used to decrease the size of
acetylene, a cylinder of oxygen, two regulators, two
8-1
