SOIL AND WASTE PIPES AND VENTS. TESTS
SOIL PIPES
The term "soil pipes" means pipe that receives the discharge from
water closets. The size of a soil pipe for ordinary dwellings
should be 4 inches.
SIZE OF SOIL PIPES
One to three closets--4-inch XX cast-iron.
Four to eight closets--5-inch XX cast-iron.
Eight to twelve closets--6-inch XX cast-iron.
There are cases when 3-inch XX cast-iron pipe is used, but the
practice is not recommended.
The soil pipe should be well supported and held in place. The
connection between soil pipe and closet should be of lead to allow
for any expansion of settling that might take place.
MATERIAL OF SOIL PIPES.--Soil pipe in common use today is made of
light cast iron, tar-coated, extra heavy cast iron uncoated and
coated, galvanized wrought-iron pipe, and steel pipe. The best kind
to use depends upon the job and place where it is to be used.
All kinds of bends and fittings can be had in any of the
above-mentioned materials. In choosing the material of the pipe
that is best to use, the following points should be carefully
considered.
_First_, new work or overhauling.
_Second_, temporary or permanent job.
_Third_, construction of building.
_Fourth_, amount allowed for cost of materials on job.
_Fifth_, size of job, that is, the number of toilets.
_Sixth_, size of chases and pipe partitions.
LOCATION OF SOIL PIPE.--The location of the soil pipe depends to a
great extent upon the location of the toilets. The soil stack
should be located on an inside partition. The horizontal pipe
should not run over expensively decorated ceilings unless run
inside of a trough made of copper or sheet lead. As far as
possible, the pipes should be confined, to runs short, and the
number of bends reduced.
SOIL-PIPE FITTINGS
Soil-pipe fittings can be had from stock almost to suit the
conditions. I will enumerate a few. The names of these fittings
should be familiar to the mechanic so that when ordering he can
give the correct name. 1/16, 1/8, 1/6, 1/4 bend, sanitary tee,
tapped tee, side outlet fitting, return bend, cross branches,
double Y, double TY, traps. The uses of these cast-iron fittings
perhaps are obvious, but a word about the use of each one will be
of service.
The 1/4 bend is used to change the direction of run of pipe 90 deg. A
long-sweep 1/4 bend is used on work requiring the best practice.
1/8, 1/16, and 1/6 bends are used to change the direction of pipe
45 deg., 22-1/2 deg., and 16-2/3 deg. Two 1/8 bends should be used in
preference to one 1/4 bend where there is sufficient room. Side
outlet 1/4 bend is used for waste connection. They can be had with
an outlet on either side of the heel. Their use is not recommended.
Return bends are used on fresh-air inlets. Tees are used for vents
only. Ys are used wherever possible. The use of a Y-branch together
with an 1/8 bend for a 90 deg. connection with the main line is always
preferable to a TY or, as they are commonly called, sanitary T. A
tapped fitting gets its name because it is tapped for iron pipe
thread. Tapped fittings are used for venting and should not be
used for waste unless the tap enters the fitting at an angle of
45 deg.
These fittings and pipe are joined by first caulking with oakum and
pouring, with one continuous pour, the hub full of molten metal.
When cool, the lead should be set and then caulked around the pipe
and around the hub.
The amount of lead and oakum required for various-sized joints is
as follows:
Pipe size 2 3 4 5 6 8 10 12 15
Pounds of lead 1-1/2 2-1/4 3 3-3/4 4-1/2 6 7-1/2 9 11-1/4
Oakum (ounce) 4 6 8 10 12 16 20 24 30
RUST JOINTS.--The plumber is called upon to run cast-iron pipe in
places where lead and oakum will not be of service for the joints.
In cases of this kind, a rust joint is made. This "rust" is made
according to the following formula:
1 part flour of sulphur.
1 part sal-ammoniac.
98 parts iron borings (free from grease).
This mixture is made the consistency of cement, using water to mix
thoroughly and bring all parts into contact with each other. When
it hardens, it becomes very hard and makes a tight joint which
overcomes the objections to lead and oakum joints.
WROUGHT-IRON AND STEEL PIPE
This pipe comes in about 18-foot lengths and fittings of the
following makes and shapes, and their use is fully explained. The
lengths of pipe come with a thread on each end and a coupling
screwed on one end. The lengths come in bundles up to 1-1/2-inches
and in single lengths over that size. Screw pipe fittings, it will
be noted, are called by a different name than cast-iron ones. The
fittings in common use today are the 90 degree ell, 45, 22, and
16-2/3. The Y and TY, tucker fittings, and inverted Ys are used in
practically the same way as the cast-iron fittings. The 90 degree
ell, 45, 22, and 16-2/3 are used to change the run of pipe that
many degrees. All 90 degree fittings, ells, and Ts are tapped to
give the pipe a pitch of 1/4 inch to the foot. It is better to use
two 45 ells to make a 90 bend when it is possible.
[Illustration: CAST-IRON SCREW FITTINGS
FIG. 54.]
INVERTED Y.--The inverted Y is used in venting to good advantage.
The use of these fittings is illustrated in the sketches.
WASTE PIPES.--Waste pipes are the pipes that run to or convey the
discharge of waste matter to the house drain, from wash trays,
baths, lavatories, sinks, and showers.
The usual size of waste pipes is 2 inches. Waste pipes are made of
the same material as soil pipe. Lead and brass pipe are also in
common use. All exposed waste pipes in bath and toilet rooms are
brass, nickel-plated. The waste pipes under kitchen sinks and wash
trays are either lead or plain heavy brass. All waste pipes are run
with a pitch towards the house trap and should be properly vented
as explained under venting. The pipes should be easy of access,
with clean-outs in convenient places. The waste pipes under a tile
or cement floor should be covered with waterproof paper and a metal
V-shaped shield over the entire length. If the waste pipes are over
a decorated ceiling they should be in a copper-lined or lead-lined
box. This box should have a tell-tale pipe running to the open
cellar with the end of the tell-tale pipe left open. If waste pipes
are to take the discharge from sinks in which chemicals are thrown,
either chemical lead or terra-cotta pipe should be used. If
terra-cotta is used, it should have at least 6 inches reinforced
concrete around it and the joints of pipe made of keisilgar.
SIZE OF WASTE PIPES
Urinals 2 inches
Kitchen sink 2 inches
Slop sink 3 inches
Receptacles 1-1/2 inches
Bath tubs 1-1/2 inches
Lavatories 1-1/2 or 1-1/4 inches
Wash trays 2 inches
TELL-TALE PIPE.--The tell-tale pipe is a small pipe that extends
from the trough, pan, or box that is under a line of pipe or
fixtures to the open cellar. When water is seen running out of this
pipe, it shows that a leak exists somewhere in the line of pipe
that is in the box or trough. The use of this pipe saves the
destruction of walls and ceilings.
VENTS
[Illustration: FIG. 55.--Circuit vent.]
Vents are the most important pipes in the plumbing system. Modern
plumbing successfully attempts to make living in crowded and
thickly populated districts, as well as in isolated buildings, free
from all unpleasant odors and annoyances. This could not be
accomplished without the use of vents. Vents relieve all pressure
in the system by furnishing an outlet for the air that is displaced
by the waste discharged from the fixtures. Another of its functions
is to supply air when syphonic action starts, thereby stopping the
action that would break the seal of the trap under fixtures. The
pipe extending from top fixture connection, up to and through the
roof, is called the ventilation pipe. All vents that do not pass
directly through the roof terminate in this ventilation pipe.
To explain the use of vents, we might well start in the basement of
a dwelling house. Suppose there is a set of wash trays in the
laundry; the 2-inch trap of these trays should have a 1-1/4-inch
vent pipe leading from the crown of the trap up along side of the
stack. On the first floor a 1-1/4-inch pipe from the crown of the
kitchen sink trap will lead into it. Here the pipe should be
increased to 2 inches. On the second floor the 1-1/4-inch pipes
leading from the lavatory and bath traps come into it. The vent
stack now extends up into the attic and connects with the
ventilation pipe. In a general way, the above is an example of
venting. The old method of venting was very complicated and is
almost beyond describing with the pen.
[Illustration: FIG. 56.--Loop vent.]
In common use today, there are several kinds of venting, namely:
circuit and loop venting, crown venting, and continuous venting.
The _circuit venting_, Fig. 55, is used in connection with the
installation of closets. Take a row of toilets in which the waste
connection of each closet discharges into a Y-branch, and there
will be a series of Y-branches. One end of this series of branches
discharges into the main stack while the other end continues and
turns up at least to the height of the top of the closet and then
enters the main vent stack. When this main vent runs up along side
of the main stack and forces the vent pipe connected to the series
of Y-branches to travel back, it is called a loop vent. This type
of vent supplies air to the complete line of toilets and is very
efficient.
[Illustration: FIG. 57.--Continuous vent.]
[Illustration: FIG. 58.]
CONTINUOUS VENTING, Figs. 57 and 58, applies more to fixtures other
than toilets. A P-trap is used and enters a T in the stack. The
lower part of the T acts as and connects with the waste pipe while
the upper half is and connects with the vent pipe. A study of the
figures will aid the reader to understand thoroughly the above
explanations. In continuous venting the waste of the lowest fixture
is discharged into the vent pipe and extended to the main waste
stack where it is connected. This is done to allow any rust scales
that occasionally drop down the vent pipe, and render it unfit to
perform its duty, to be washed away into the sewer.
CROWN VENTING, Fig. 59, is as its name implies, a vent that is
taken from the crown of the trap, thence into the main vent.
Each one of these methods of venting is used and considered good
practice, provided it is properly installed and correctly connected
with the use of proper fittings.
[Illustration: FIG. 59.--Crown venting.]
THINGS TO REMEMBER.--
_First_, venting is to prevent traps from syphoning.
_Second_, also to allow free passage of air.
_Third_, circuit vent--loop vent.
_Fourth_, continuous venting.
_Fifth_, crown venting.
_Sixth_, ventilation pipe extends from the top of fixture through
roof.