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.
As before stated, all the water used in the building, except for some purposes in the basement and cellar, is ordinarily first pumped up to the twenty-first story, and is either distributed from there by separate lines that run from those tanks to all fixtures above the tenth floor or is drawn (through an overflow pipe) to an open eleventh-floor tank that supplies all lower stories, thus reducing the maximum pressure to about 70 pounds, or one-half of what would be due to the extreme height from the pumps to the upper tank. The eleventh-floor tank serves merely to regulate the head and store a small supply, hardly more than enough to insure abundant provision for sudden severe draft. It is not conveniently accessible for constant examination and regulation, and is so arranged as never to require any attention except in case of accident or periodical inspection and cleaning unless some unusual necessity occasions it to be filled direct from the pumps or to be cut out of service, when its valves would have to be reversed. Its discharge pipe, the falling main shown in Figs. 6, 7, 8, is connected in the basement machine-room with the hot and cold water drums shown in Fig. 9, and also outlined in Fig. 2. These drums also have a direct connection to the street-pressure supply by a 4-inch pipe, in which a check valve is set, opening towards the drums so that tank water could not escape into the street through it if its valve should accidentally be left open. From these drums separate rising mains are carried as required for all the water supply, for plumbing fixtures, up to the eleventh story. The cold-water drum is of steel tested and guaranteed to 600 pounds pressure per square inch; it is 24 inches in diameter by 74 inches long, with manhole and cover, and is supported on iron standards.
The rising mains vary in size according to their required service, and in some instance diminish in size upwards, starting, for example, as for line B, at 1½ inches up to the sixth floor, and thence running 1¼ inches to the ninth floor, the section being thus proportioned to the fixtures beyond it. The construction of drums and connection of manifold tor the convenient connection of pipes, the arrangement and valving of risers, and provision of drip pipes for cutting out and emptying any line, are clearly shown in Fig. 9. An air vent and pressure relief is secured by extending a 1- inch pipe up from the top of one of the risers and turning it over open above the top of the house tank. Besides the services mentioned distribution is made for boiler-feed pumps, injectors, elevator pit pump, drips, and blow-off tanks, etc., by means of a receiving tank in the subcellar, from which the water is automatically discharged into the sewer by means of a float-valve connected pump. All pipes to pumps and hot and cold water drums are connected up with ground brass flanged unions, so that repairs can be made without disturbing the runs of pipes.
PLUMBING IN THE AMERICAN SURETY BUILDING, NEW YORK CITY.
Adjacent to the cold-water drum is a hot-water drum, 24x76 inches, tested and guaranteed to 600 pounds pressure per square inch, and provided with a manhole and cover. Inside this drum is a single loop of large, heavy brass pipe connected with both live and exhaust steam mains and drips to a steam trap and floor drain. The steam supply pipe has a hand valve and is also commanded by a Powers automatic regulating attachment adjusted to shut off steam when the temperature of the water exceeds 200 degrees. This drum is supplied like the cold-water one, from the intermediate eleventh-floor tank, and distributes hot water through similar risers connected to its upper manifold to all the lavatories up to the eleventh floor, and to all the isolated washbasins up to the seventh floor. From the top of each of these rising lines a return circulation pipe one size smaller than the smallest or uppermost section of the hot water pipe is brought directly down to the lower manifold that communicates with the drum as shown by the two 3-1nch branches similarly to the flow connections above. A vent and relief pipe is carried from the top of one of the risers and inverted, open, above the house tank.
All flow, circulation, and drip pipes are symmetrically arranged and valved as shown so as to permit the independent operation and emptying, and the drum is cased with non-conducting covering A hot-water supply for the upper part of the building is secured without increasing extreme pressure on the basement heater or lower parts of the pipes by the unusual expedient of making an intermediate heating system and distributing hot water for the upper service from an elevated heater. To this end a No. 3 Berryman feed-water heater is set on steel crossbeams built into the walls of the ventilating shaft in the ninth story and connected up as shown in Fig. 10. Just below the back-pressure valve in the exhaust pipe, which is set at five pounds, a branch is taken out and steam supplied through a pressure regulating valve set at three pounds. Steam circulates from the heater into the main exhaust pipe above its back-pressure valve and escapes freely into the atmosphere above the roof. Both steam pipes have a 2 inch drip connection, and the heater may be emptied through a 2 inch mud pipe, another 2 inch pipe is provided for a surface blow-off and the cold water is introduced in the power part of the heater opposite to the entrance of the two return circulation pipes.
The cold-water supply pipe is taken directly from the manifold at the twenty-first story tank as shown in Fig. 4. The two hot-water distribution mains supply all the main toilet-rooms from the tenth to the twentieth stories inclusive, and together with the return circulation pipes are run horizontally in a wood box lined with four-pound sheet lead, with a water-tight cover of 18 ounce copper with the edges turned over and hermetically sealed. Under the heater is placed a heavy sheet-iron drip pan, connected with the above-mentioned box, which has a 1½ - inch waste pipe emptying into a slopsink on the eleventh floor. The horizontal portions of the pipes are placed on rollers and firmly secured at the center with the ends left free to act. Each of the supply and circulation pipes is provided with valves so that they may be turned off independently. The pipes and heater drain into the nearest waste line. The pressure regulating valve in the branch supplying steam to the heater has a three-pound counterweight opposed to its regulating weight so that it is about balanced, and it is connected to a thermostat inside the heater, set so as to shut off steam when the temperature of the water rises to 200 degrees.