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.
City water is received through two 3-inch Thomson meters, one on a pipe from the Twenty-third Street main and one on a pipe from the Madison Avenue main. These supplies unite inside their meters to deliver to two No. 5 Loomis filters, which work under pressure and discharge through a 4-inch pipe, and from 1½-inch ball cocks into a 3,000 gallon open iron suction tank at the pump level in the subbasement about 30 feet below grade. From this tank the water is pumped about 200 feet high into a 6,000-gallon iron roof tank, from which it is delivered back to the basement in two vertical pipes. One 3-inch line supplies the 2½ inch hose cocks for fire service on every floor, and has also direct pump connection duplicated to four separate pumps, and the other 3-inch line leads to a distributing drum in the cellar, whence horizontal branches supply riser lines up to the different groups of fixtures. The pumps are all duplicated, and the three pairs for house tank, cistern, and boiler-feed service are interchangeably connected, and are used alternately so as to keep each one in regular working order.
Figure 2 shows conventionally the general arrangement of the vertical soil and vent lines, the position of the branches and fixtures being sometimes revolved into a different vertical plane to bring them into side view. All soil pipes are shown by double lines, all waste pipes by full heavy lines, and all trap vent pipes by dotted lines. A and B are respectively the lines for the closets and washbowls in the principal toilet-rooms (see Fig. 1, seventh story, p. 210). C and D are lines serving the janitors' closets, which contain slopsinks, basins, and water-closets. I is a line direct for one set of washbowls, and having branches through the floor under the doors to basins in adjacent rooms through which no vertical pipe was carried. J and N are lines to office washbasins in the upper floors, and P is a line with double horizontal offsets to avoid passing through a wide open floor space in the lower stories.
Figure 3 shows the arrangement of the filter plant. Each filter has a rated capacity of 1,280 gallons a day, and receives its supply through pipe A and delivers it through pipe B. By reversing lever D the discharge valve is closed, and the filter is washed until the escaping water to the subdrainage cistern seen through glass C becomes clear. E is a small tank to contain alum, which can be introduced into the supply through pipe H, in proportions controlled by the graduated lever F. Figure 4 shows the connection of one of the duplicate Worthington house pumps, the discharge of which is also connected to the boiler- feed and fire-line pipes. A A A, etc. are emptying pipes which are carried down below the concrete floor and discharge into the broken stone surrounding the cistern, where the subsoil waters are all collected. Ordinarily all the discharge valves are closed except F, and the throttle valve is left open so that steam may be freely admitted to valve G, which is automatically controlled by the Ford's pump governor B, which consists essentially of a piston-rod attached to the stem of the gate valve and held open by a spring. When the tank is full it overflows through the 1-inch telltale C just below the level of its main overflow, and exerts a pressure through E that drives the piston down in cylinder H and shuts off steam until, the overflow clearing, all the water in the telltale escapes and the valve is opened by its spring.
Figure 5 shows the connection of the pair of alternate pumps that lift the water from the cistern to the flush tank reservoir on the roof or discharge it to the sewer. A third pipe delivers it to the street washing hose, which is usually supplied with Croton water to avoid danger of discoloring the marble front. It has an automatic regulating valve G corresponding to that shown in Fig. 4.
Figure 6 shows the arrangement of house tanks for general purposes and for flushing. The flushing tank is set a few inches higher than the former so that its safe waste can discharge into the pan of the former. Both are of the usual riveted boiler-plate construction with internal tie-rods, and are intended to be always pumped full, the pumps being arranged to work automatically until the water escapes through the telltale, which is the only provision for indicating the height of water. The two tanks are entirely independent, and the connection between them is usually closed, but may be opened to admit water from either tank into the other. B is an expansion pipe to relieve the hot-water boiler, which can blow off into the tank. V V, etc. are vents to promote the emptying of riser lines, and C is a check valve opening away from the tank, to permit constant tank pressure on the fire line and to close against direct pump pressure from below and permit the fire pump to operate without wasting water through the tank.
Figure 7 shows the large steel drum, about 30x50 inches, in the subbasement, through which all the cold water supply for the building passes and is delivered through branches E and F to horizontal pipes, each of which half encircles the building and distributes the water to the different riser lines D D, etc. These can be independently cut off, and may be drained through pipes C C, etc. Ordinarily valve A is closed and B is open, but in an emergency valve A may be opened and B closed to shut off the tank, and the street water will supply the system as high as its pressure limit, and the check valve will prevent any escape into the street when it fluctuates.