GAS FITTING, PIPE AND FITTINGS, THREADING, MEASURING, AND TESTING
GAS AND ITS USE IN BUILDINGS
Gas is in common use in all classes of buildings today. Dwellings
use it for cooking and illuminating, factories, office buildings,
and public buildings for power. In some parts of the country
natural gas is found. In these places it is used freely for heating
fuel. The actual making of gas is something that every plumber
should understand. If space permitted I would describe a gas plant
with all of its by-products. However, we shall deal only with the
actual installation of gas piping in buildings. Gas mains are run
through the streets the same as water mains are run. Branches are
taken off these mains and extended into the buildings requiring
gas. The gas company generally installs the gas service pipe inside
of the basement wall and places a stop cock on it free of charge.
This stop that is placed on the pipe is a plug core type, the
handle for turning it off is square, and a wrench is required to
turn it. The square top has a lug on it. There is also a lug
corresponding to it on the body of the valve. When the valve is
shut off, these two lugs are together. Each lug has a hole in it
large enough for a padlock ring to pass through. This gives the gas
company absolute control of the gas in the building.
SETTING OF THE METER.--Every building that is supplied with gas has
a meter that registers the amount of gas consumed. This meter is
placed on the service pipe on the house side of the above-mentioned
stop cock. This meter is furnished free of charge with a trivial
charge made for setting up. The actual setting of this meter is not
made until the piping throughout the building has had a thorough
and satisfactory test and is found free from all leaks. The meter
must be set level on a substantial bracket and in a place, if
possible, where it will not require an artificial light to read its
dial. The dry meter is usually used in dwellings. The interesting
construction and mechanism of this meter cannot be discussed here.
[Illustration: FIG. 77.--Gas-meter dials.]
The reading of the dials on a gas meter comes in the province of
the plumber and he should be able to read them. The sketch shows
the dial plate of a meter. The ordinary house meter has only three
recording dials. Large meters have five or more. To read the amount
of gas consumed according to the meter we will read the dials as
they are indicated on Fig. 77. We will call the four dials No. 1,
No. 2, No. 3 and No. 4. In each of these dials a complete
revolution of the index hand denotes 1,000, 10,000, 100,000 and
1,000,000, cubic feet respectively. The index hands on No. 1 and
No. 3 revolve in the same direction, while No. 2 and No. 4 revolve
in the opposite direction. Two ciphers are added to the figures
that are indicated on the dials and the statement of the meter will
be had. To tell just how much gas has been consumed in a given
time, the statement of the meter is taken at the beginning of this
given time and at the end of the time. The difference in the
figures indicates the number of cubic feet of gas that have been
consumed. A gas cock should be placed on the house side of the
meter. The dials of meter read 658,800 cubic feet. The dial having
the highest number is read first No. 4 dial points to 6, this
indicates that No. 3 dial has revolved 6 times. Dial No. 3 reads 5,
therefore the reading of dial No. 3 and No. 4 is 65. Dial No. 2
reads 8 making the readings of the three dials 658. Dial No. 1
reads 8 making the readings of the four dials 6588 add two ciphers
to this figure and 658,800 is the correct reading.
[Illustration: FIG. 78.]
[Illustration: FIG. 79.]
PIPE AND FITTINGS.--The pipe used in gas fitting is wrought iron or
steel. In special places, rubber hose is used. Brass pipe is
occasionally used to advantage. The fittings used in iron pipe gas
work should be galvanized. No plain fittings should be allowed. The
plain fittings very often have sand holes in them and a leak will
result. Sometimes this leak does not appear until after the piping
has been in use some time and the expense of replacing the fitting
can only be guessed at. By using galvanized fittings, this trouble
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 sketch of a dwelling, and if they were to be actually
put in, they would fit. The reader would do well to copy this
sketch and follow the piping and check the measurements according
to the plan, and note how the different risers, drops, etc., are
drawn. It is not necessary in a sketch of this kind to draw to a
scale. After the different measurements are the letters _C.C._,
_E.C._, _E.E._, _C.B._ and _E.B._, meaning center to center, end to
center, end to end, center to back, and end to back, respectively.
Offsetting pipe is a very convenient way of getting the pipe or
fittings back to the wall for support. To offset pipe properly and
with little trouble, take a piece of scantling 2 by 4 and brace it
between the floor and ceiling. Bore a few different-sized holes
through it and you will have a very handy device for offsetting
pipe. There is a little trick in offsetting pipe that one will have
to practice to obtain. The pipe must be held firmly in the place
where the pipe is to be bent. Large offsets and bends should not be
made; 2 to 4 inches is as large as should be used. Larger offsets
that are required should be made with fittings. Always make the
offsets true and have the ends perfectly straight. Before putting a
piece of pipe permanently in place, always look or blow through it,
to ascertain if its bore is obstructed or not. Sometimes dirt or
slag will collect and cause stoppage.
READING THE PIPE SKETCH.--Vertical lines represent vertical pipes
(see Fig. 81). Horizontal lines represent horizontal pipes running
parallel to the front. Diagonal lines represent horizontal pipes
running from back to front. Any line that is drawn perpendicular to
any other line stands for a horizontal pipe. A diagonal line
separating a vertical line or horizontal line or set of lines
represents a different horizontal plane. With this explanation the
sketch will be made clear to one after drawing it. The reader
should now take each measurement and check it on the plan. This is
easily done by using a scale rule. The height of the ceiling is
8-1/2 feet on the first floor, the second floor is 8 feet. The
first floor joists are 10 inches, the second floor joists are 9
inches. An outlet is indicated by a small circle. In the piping
sketch, this circle is connected with the riser or drop by a
horizontal line. At the junction of these two lines a short
perpendicular line is drawn, and indicates the direction of the
outlet.
Let me again emphasize the need to understand thoroughly this
piping sketch, and to become so familiar with it that it can
readily be put to use. The value of a mechanic is determined by the
quality and the quantity of work that he can turn out; and a
mechanic who can lay out his work and see it completed before he
starts, and then proceeds to install his work, is by far of more
value to his employer than the man who can see only far enough
ahead to cut out two or three measurements and spends most of his
time walking between the vise and place of installing the pipe.
TESTING.--The system of gas piping must be tested before the pipes
have been covered by the advance of building operations. If the job
is of considerable size, the job can be tested in sections, and if
found tight the sections can be covered. The necessity of having
the piping rigidily secured can be appropriately explained here. If
the test has been made and the system found tight and some pipe
that is not securely anchored is accidentally or otherwise pushed
out of place and bent by some of the mechanics working about the
building, a leak may be caused and yet not discovered until the
final test is made after the plastering is finished. The expense
and trouble thus caused is considerable and could have been avoided
by simply putting in the proper supports for the pipe.
To test the piping, an air pump and a gage connected with the pipes
are placed in a convenient position. The job should now be
thoroughly gone over, making sure that all plugs and caps are on
and that no outlet is open, also that all pipe that is to be put in
has been installed. After this has been attended to, the pump is
operated until 10 pounds is registered on the gage. The connection
leading to the pump and the piping is now shut off. If the gage
drops rapidly, there is a bad leak in the system. This leak should
be found without difficulty and repaired. If the gage drops slowly,
it denotes a very small leak, such as a sand hole or a bad thread.
This kind of leak is more troublesome to find. When it has been
found, the pipe or fitting causing the leak should be taken out and
replaced. If black caps have been used to cap the outlets, the
chances are that a sand hole will be found in one of them. Nothing
but galvanized fittings should be used. In case the small leak
mentioned above cannot be found by going over the pipe once, there
are other means of locating the leak. Two of the methods used, I
will explain. If the job is small, each fitting is painted with
soap suds until the fitting is found that causes the leak. If the
leak is not in the fittings, then the pipe can be gone over in the
same way. As soon as the soap suds strikes the leak, a large bubble
is made and the leak discovered. It is possible that there are more
leaks, so the gage is noted and if it still drops, the search
should be continued. The pump should be operated to keep the
pressure up to 10 pounds while the search is being made for the
leak. When the gage stands at 10 pounds without dropping, the job
is then tight. The pump and gage fitting should be gone over first
to ascertain if they leak. The other method employed to discover
leaks is to force a little ether or oil of peppermint (not essence)
into the system by means of the pump. A leak can readily be noted
by the odor. To make this method successful, the ether or
peppermint should not be handled by the men who are to hunt for the
leak. The bottle containing the fluid should not be opened in the
building except to pour some into the piping, otherwise the odor
will get into the building and as the odor comes out of the leak it
will not be noted. For the benefit of the gas fitter, the piping
should be tested again after the plastering is completed. The next
test is made when the fixtures are put on, and as the piping is
tight any leak that develops in this test indicates that the
fixtures leak. There are in common use various methods to stop
leaks in gas pipe when they are found. If a piece of piping or a
fitting is defective, it should be taken out and replaced. This
should be remembered so that while the piping is being installed
any defects should be noted and the defective fitting or pipe
thrown out. Before the gas job is accepted, the gas company will
inspect it and look for traps and sags in the pipe. Therefore, the
piping should be installed without any traps and it should be
arranged to pitch toward the meter, or toward a convenient place
from which any condensation can be taken out. If provision is not
made for this condensation, it will accumulate and stop the flow of
gas.
SHOWER-BATH CONNECTIONS
[Illustration: FIG. 82.--Shower stall with lead pan extending
outside of stall.]
The sketches show clearly the methods employed to make a
shower-bath waste and stall water-tight. The shower bath, as a
separate fixture, is in use and the demand for it as a separate
fixture is increasing rapidly. This demand comes from the owners of
private houses. The plumber must therefore devise some way to make
these connections tight and prevent any leak from showing in the
room below. This fixture is so constructed that all waste pipes
and trap come under the floor level with no way of getting to them
from below. Therefore the piping for this fixture must be of a
permanent nature. No pipe or trap made of material that is liable
to give out in a short time should be allowed under a shower-bath
fixture or stall. The two sketches, Figs. 82 and 83 illustrate two
methods of connecting and making tight a shower stall. A plumber
should always consider it his special duty to make his work
complete and free from all objections. He should always prepare for
any emergency that may occur in the future. This is rather a big
task, yet the plumber when accepting all of his responsibilities
has a big task. I state this to the beginner and emphasize the
all-important fact that he must learn to perform and think deeply
of the elements of plumbing to be able later on to handle
successfully the problems that present themselves in the plumbing
trade.
[Illustration: FIG. 83.--Shower stall with lead pan extending six
inches beyond strainer.]
The heavy brass trap shown in the sketch has proved itself very
satisfactory and can be made to fit almost any condition of piping
or building construction. A flashing of sheet lead is soldered on
the trap and carried out to the outside edge of the stall where it
is turned up 1 inch, or to the floor level. When the flashing is
carried out for only a foot on each side of the trap, the
possibilities of a leak are greater.