ble
will be eliminated. All fittings used should be of the beaded type.
The fitting and measurement of this work is practically the same as
described under iron pipe work. To have the beginner get a clearer
idea of gas-piping a building, the piping of the small building
sketched will be gone over in detail and studied. One of the first
important steps that a gas fitter is confronted with is the
locating of the various lights and openings. With these located as
shown on the plan, Figs. 78, 79 and 80, we will proceed to work
out the piping. The first floor rise will be 1-inch, the second
floor will be 1-inch. The horizontal pipe supplying the first floor
outlets will be 3/4-inch pipe. The horizontal pipe on the second
floor will be 3/4-inch. The balance of the pipe will be 3/8- or
1/2-inch. At this point your attention is called to the sketch of
piping, sizes, and measurements. This sketch should be studied and
understood in detail. The good mechanic will employ a sketch of
this kind when installing any piping. The poor mechanic will take
two or three measurements and get them out, put them in, and then
get some more. This method is extremely costly and unworkmanlike.
There is no reason, except the ability of the workman, why he
cannot take a building like the sketch and get all the piping
measurements for the job, then get them out, go to the job and put
them in. The amount of time saved in this way is so great that a
workman should not consider himself a full-fledged mechanic until
he can get the measurements this way, and get them accurately. With
a tape line, gimlet, and plumb-bob, a mechanic is fully equipped
with tools to get his measurements. If the measurements are taken
with a tape line, the same tape line should be used when measuring
the pipe and cutting it. When laying out the piping, never allow a
joist to be cut except within 6 inches of its bearing. It is good
policy never to cut timber unless absolutely necessary and then
only after consulting with the carpenter. When joists have to be
notched they should be cut only on the top side. The pipe as it is
put in place should be braced rigidly. Wherever there is an outlet
pipe extending through the wall, the pipe should be braced from
all sides so that when the fixture is screwed in it will be
perfectly rigid.

[Illustration: FIG. 80.]

[Illustration: FIG. 81.--Pipe sketch.]

The measurements on the piping sketch, Fig. 81, are taken from the
accompanying