Fig. 159.
Lead is one of the elementary substances of which the world is formed; it ranks with gold, silver, tin, etc., in being an unmixed metal. It melts at about 617° Fahrenheit, and is, bulk for bulk, 114⁄10 heavier than water (gold being 175⁄10 heavier and wrought iron 77⁄10 heavier). The tenacity of lead is extremely low, a wire 1⁄18th of an inch breaks with a weight of 28 lbs.; in comparison, its tenacity is only one-twentieth that of iron; it is so soft that it may be scratched with the thumb nail. If a very strong heat is applied lead boils and evaporates; it transmits heat very slowly; of seven common metals it is the worst conductor, therefore it is good for hot water pipes. Mixed with a sufficient quantity of quicksilver it remains liquid.
An advantage to be found in the use of lead is its durability and comparative freedom from repairs. In London, soil and drain water pipes which have been fixed 300 to 500 years are as good now as the day they were first made—while iron pipe cannot be expected to last over 10 or 20 years or 30 at the utmost.
[Fig. 159] represents the general system of house piping and drainage applicable also to shops, public buildings, etc. A exhibits the drain or sewer. A-C represents the sewer connection, so called with a running trap, B. “C” at the end of the lower pipe exhibits a soil pipe elbow, with hand hole for cleaning out closed by a screw plug. This drain should have a regular fall or inclination and this elbow provides for that. C-D shows the rain water leader (conductor).
E and F is a soil pipe 3, 4, 5, or 6 inches in diameter. Note, pipes draining water closets are called “soil pipes”; those draining other fixtures “waste pipes.” N and O represent water-closet flanges; F and H are roof connections; L exhibits double and single Y branches to receive waste-pipes from baths, bowls, or sinks. The plumber makes this connection, always trapping the lead waste-pipe and then soldering it to a brass nipple.
LEAD PIPE JOINTS.
Fig. 160.
It has been remarked that after learning how to make “a wipe joint,” everything is easy relating to the plumber’s trade; hence, the importance of the following directions.
To learn the art, previous practice with short pieces of pipe is recommended. This trial piece can be clamped as shown in [Fig. 160] and used over and over until practice has been had.