Figure 4-27.Cutting pipe with an oxygas cutting torch.
you should do the following: promptly turn off the
cutting oxygen, turn off the current, and extinguish the
flame-in that order. The cutting speed depends upon
the thickness of the steel being cute
CUTTING AND BEVELING PIPE
Pipe cutting with a cutting torch requires a steady
hand to obtain a good bevel cut that is smooth and true.
Do not attempt to cut and bevel a heavy pipe in one
operation until you have developed considerable skill.
First, you should cut the pipe off square, and ensure all
the slag is removed from the inside of the pipe. Next,
you should bevel the pipe. This procedure produces a
cleaner and better job; it is ideal for use by an inexperi-
When cutting a piece of pipe, you should keep the
torch pointed toward the center line of the pipe. Start the
cut at the top and cut down one side. Then begin at the
top again and cut down the other side, finishing at the
bottom of the pipe. This procedure is shown in figure
When you make T and Y fittings from pipe, the
cutting torch is a valuable tool. The usual procedure for
fabricating pipe fittings is to develop a pattern like the
one shown in figure 4-28, view A-1.
After you develop the pattern, wrap it around the
pipe, as shown in figure 4-28, view A-2. Be sure to leave
enough material so the ends overlap. Trace around the
pattern with soapstone or a scribe. It is a good idea to
mark the outline with a prick punch at 1/4-inch intervals.
During the cutting procedure, as the metal is heated, the
punch marks stand out and make it easier to follow the
line of cut. Place the punch marks so the cutting action
will remove them. If punch marks are left on the pipe,
they could provide notches from which cracking may
An experienced Steelworker can cut and bevel pipe
at a 45-degree angle in a single operation. A person with
little cutting experience should do the job in two steps.
Figure 4-28.Fabricating a T.
In that case, the first step involves cutting the pipe at a
90-degree angle. In the second step, you bevel the edge
of the cut to a 45-degree angle. With the two-step
procedure, you must mark an additional line on the pipe.
This second line follows the contour of the line traced
around the pattern, but it is drawn away from the original
pattern line at a distance equal to the thickness of the
pipe wall. The first (90-degree) cut in the two-step
procedure is made along the second line. The second
(45-degree) cut is made along the original pattern line.
The primary disadvantage of the two-step procedure is
it is time consuming and uneconomical in oxygen and
The one-step method of cutting and beveling pipe
is not difficult, but it does require a steady hand and a