This section is from the book "American Plumbing Practice", by The Engineering Record. Also available from Amazon: Plumbing: A working manual of American plumbing practice.
All fixtures should be trapped with bend traps, and. all traps should be back aired from the crown of the trap. If brass traps are used, they should have ground brass couplings only. Traps with rubber or leather washers should not be used; they cannot be made permanently secure. Earthenware closets and other fixtures having the trap formed in the earthenware should have short lead bends connecting with the iron pipe. This admits of settlement in the-floors without breaking the earthenware.
Connect lead with iron pipes by a wiped solder joint and brass ferrule calked into the hub of iron pipe.
All back-air branches from traps should be connected into T or reversed Y branches on the back-air column; these branches to be placed above the fixtures from the trap of which the back-air branch is taken. This prevents the fixture discharging through the back-air pipe if the waste pipe becomes choked.
All lead or metal traps should have a brass screw cleanout below the seal of the trap.
After all the iron-work is completed, and traps and back-air connections and bends have been connected, all of the traps and bends and other openings must be securely sealed and the main drain and fresh-air inlet plugged outside of the house. The entire system of pipes and branches should then be filled with water to the level of the top of the pipes above the roof. The entire system of pipes should then be carefully inspected while under this water test, and any leaks discovered in the joints must be made tight by calking the lead home. Any split hubs and pipes or fittings with sandholes must be broken out and replaced by sound material, and the test repeated until the entire work stands the test without showing leaks of any description. The fixtures may then be permanently set and connected. On final completion of the work, and after all traps have been filled with water, a smoke test or peppermint test should be applied to the drains to test the connections not subjected to the water test. This applies especially to connections with earthenware fixtures and brass trap connections.
PRINCIPLES TO BE OBSERVED IN PLANNING AND SPECIFYING PLUMBING FOR A COUNTRY HOUSE.
The joints in the iron pipe and fittings should be made by firmly calking a roll of oakum into the joint between the hub and spigot, care being taken to p-event the oakum entering the bore of the pipe. The joint must then be run full with pure soft lead, which must be firmly calked home when cold. Tbe joint must be level with the face of the hub when finished.
All pipes should be run as direct as possible and the fixtures planned to lie close to the main pipes and avoid long branch connections.
All pipes and fixtures should be left as much exposed as possible and with the least amount of joiner-work and boxing, and with the least amount of absorbent material about them. Fixtures should be located so as to avoid running Water-supply pipes on outside walls where they are exposed to frost.