aced
near each side of unions so that when the union is taken apart
neither side of the pipe will drop and bend. Hooks and straps
should be used to hold vertical pipes rigid and in position. A
vertical pipe should be so held in place that its weight will come
on the hooks and straps that hold it rather than on the horizontal
pipe into which it connects. Where there are six or eight
horizontal lines of pipes close together, a separate hanger for
each pipe makes a rather cumbersome job and it consumes
considerable time to install them properly. A hanger having one
support run under all the pipes will allow space for proper
alignment and adjustment for drainage. Allowance must be made on
all lines of pipe for drainage. When a building is vacant during
cold weather, the water is drawn off; therefore, the pipes should
have a pitch to certain points where the pipes can be opened and
the entire system drained of water.

KINDS OF PIPE.--The kind of pipe that is used for cold-water supply
depends on and varies according to the kind of water, the kind of
earth through which it runs, and the construction of the building.
Wrought iron, steel, lead, brass, tin-lined brass, are in use.

The supply pipe to every fixture should have a stop on it directly
under the fixture. This will allow the water to be shut off for
repairs to the faucet without stopping the supply of other
fixtures.

The making of perfect threads on pipe is an important matter,
especially on water pipes. If the pipe and the dies were perfect,
and the mechanic used sufficient oil in cutting, and the fittings
were perfectly tapped to correspond to the dies used on the pipe,
of course a perfect union between pipe and fitting would result and
the joint would be found to be perfect on screwing the pipe home.
As all the above conditions are not found on the job, threads are
made tight by the use of red or white lead and oil. The lead is put
on the thread and when the thread is made up the lead will have
been forced into any imperfection that may be in the threads and
the joint will then be water-tight. White lead and oil should be
used on nickel-plated pipe as other pipe compounds are too
conspicuous and look badly. A pipe compound should be used with
discretion, for if too much is put on a burr of it will collect in
the bore of the pipe and reduce it considerably. This is not
tolerated, so only a small amount is used. Water pipes should be
run in accessible places,