ir.

_Fifth_, keep away from windows and intake of heating system.

_Sixth_, always have end of pipe covered with strainer, cowl, or
return bend.

_Seventh_, make as few bends as possible.

_Eighth_, supplies fresh air to system.

DRUM TRAP

The use of the drum trap is very handy to the plumber as well as
efficient and practicable when installed. The trap can be purchased
without any outlets or inlets, so the plumber can put them in
according to the necessary measurements. The making of these traps
with lead is explained in the chapter on Wiping Joints. The open
end has a brass clean-out screw on it. When this clean-out screw
comes below the floor, another brass screw cap and flange is
screwed on the floor above the trap so that the clean-out screw in
the trap is easily accessible.

[Illustration: FIG. 61.--Drum trap.]

These drum traps are called bath traps as they are used mostly on
bath wastes. They should never be installed with the clean-out
exposed to the sewer side of the trap. In the best practice, heavy
brass drum traps are used.

NON-SYPHONING TRAP

[Illustration: FIG. 62.--Flask trap.]

[Illustration: FIG. 63.--Clean-sweep trap.]

After years of experimenting to produce a trap that would not
syphon without venting, we find in use today a large variety of
non-syphoning traps. Traps that will hold their seal against all
practical forms of syphonic action, or other threatening features,
have been made and used and serve the purpose for which they are
intended. Various means to prevent the breaking of the seal of
these traps are employed. While some depend on a ball or other kind
of valve, others rely on partitions and deflections of various
kinds. All of these perform the functions for which they are
designed, yet the devices employed offer an excellent obstruction
for the free passage of waste; therefore, in time, these traps
become inoperative. It should be borne in mind that any traps with
a mechanical seal or an inside partition are not considered
sanitary. The inside partition might wear out or be destroyed and
thus break the seal without the knowledge of anyone and allow sewer
gas to enter the room. The mechanical device may also be displaced
or destroyed, leaving the trap without a seal. If the trap were
cleaned out often or examined occasionally, these traps could be
used with a greater degree of safety. Some of the forms of
non-syphon traps in common use ar