Figure 5 shows the arrangement of suction tank, pumps and main pipe connections. Water from both the Fifth Avenue and Eighteenth Street mains is taken in through 4-inch branches each of which has a 4-inch meter with a check valve on the outlet side of the meter set so as to prevent water from one main escaping through both meters and into the other main if it should be broken or emptied, or to prevent a crossflow when the pressure in the two mains varies. Each main is separately controlled by a valve and can independently fill the suction tank through four 2½-inch ball cocks. The suction tank is about I2'x7'x8' deep, made of ⅜-inch steel plates, with tee-bar and angle-iron stiffeners and cross tie-rods, and holds about 5,000 gallons. It is considered an open tank in that it is provided with an overflow, and the water it contains is not under pressure, but it is tightly closed with an iron-plate cover to keep out dust, and has a hinged manhole door to give access to the interior. All its pipe connections are made with inside and outside flanges and the galvanized-iron 4 inch overflow and 2-inch emptying pipes (not shown here) are run to the receiving tank, which is set below the basement floor. It is made of boiler-iron and is about 14'x9'x5' deep, with riveted iron cover with two manholes with heavy cast-iron covers flush with the floor. This tank receives surface drainage from the light court engine-roorn floor, and overflows from all basement tanks, etc., and is pumped out to the sewer. The pumps are connected as shown, to be supplied either from the street main direct or usually through the suction tank, and are connected together for regular house and fire service and cross-connected to re enforce the boiler feed pumps if necessary. There are in all five Blake duplex pumps. The two 10"x4½"x12" shown are for fire and house service, two 6"x4"x6" for boiler feed, and one 6"x4"x6" for receiving tank, drip tanks, etc.

Figure 6 shows the connection of pipes to the roof tank and the connections to the pumps. When the tank is full its rising main is closed by the ball cock B and is immediately subjected to pressure by the action of the pump. This pressure is instantly transmitted through the small pipe P to the Kieley automatic regulating valves V V, which shut off the steam and the pumps stop. As soon as the water in the tank is lowered, the ball cock opens, the pressure in the pump discharge pipe, and consequently in pipe P, is relieved, valves V V are opened by springs, and the pumps immediately start up. Of course the automatic valves V V are provided with by passes, and the pumps can be governed by hand or arranged to work up to a heavy fire pressure much in excess of the pressure of the tank head.

The 6 500-gallon house tank is about I6'x7'6"x8' deep, constructed of tank steel plate, with all seams riveted and calked. It is stiffened and braced by T bars set vertically about 4 feet apart round the tank, and with two sets of tie-rods. Heavy 3X3-inch angle iron is riveted round the top, and the tank is covered with ¼ - inch plates (not here shown), with two large manholes with frames and covers. All pipe connections to tank are made with inside and outside riveted flange joints. The galvanized standing overflow pipe opens with a large copper funnel about 6 inches below the top of the tank and runs down to the main roof, with a metal flap over the opening. The tank-room floor is protected by an iron pan, which wastes through a 3-inch galvanized-iron waste pipe into the tank overflow. A separate ¾ - inch galvanized pipe is connected with a Schmidt's best pattern hydraulic indicator gauge, set in the boiler-room to show the depth of water in the tank in feet and inches.