welding; (2) precautions concerning the operation of
A2.0-68. Some of the symbols, but not all, have
equipment; and (3) precautions related to the safety
been changed by AWS A2.4-79. View B shows the
new symbols for those changed. No figure is shown
in view B for those symbols that were not changed.
The safety precautions given here are general in
You should be aware that some drawings available
nature and should be supplemented by study of the
may still show the symbols that were changed.
precautions given in chapter 1 of this manual and
NSTM, chapter 074, volume 1.
An assembled WELDING SYMBOL consists of
the following eight elements (or as many of these
LOCATION OF WELDING
elements as are required): (1) reference line, (2)
arrow, (3) basic weld symbols, (4) dimensions and
A first consideration for safety in welding is the
other data, (5) supplementary symbols, (6) finish
symbols, (7) tail, and (8) specification, process, or
location and peculiarities of the space in which the
other reference. The finish symbols indicate the
welding operation is to be performed. Welding and
method of finish, not the degree of finish. The
cutting may be performed ONLY in locations
specifically designated for this purpose, unless
letter C is used to indicate finish by chipping, M
indicates machining, and G indicates grinding.
approval of the job and the precautions taken to
eliminate fire and explosion hazards have been
obtained from the proper authority.
The elements of a welding symbol have standard
locations with respect to each other, as shown in
Fire and explosion hazards are eliminated by
removing or protecting combustible or explosive
materials or vapors, and by taking the precautions
necessary to prevent a reaccumulation of such
materials. The methods for making a space safe for
Safety precautions for welding may be
welding and the tests used to ensure that a space is
considered as falling into three general categories:
f r e e of fire and explosion hazards are the
(1) precautions with respect to the location of the
responsibility of the gas-free engineer, whose duties
Figure 7-27.--Standard location of elements on a welding symbol.