Blow-off Cock.
—When a considerable amount of sediment is carried in the water the range boiler acts as a settling tank and the deposit accumulated at the bottom will in time amount to a source of trouble. The accumulation is shown in Fig. 114. The part W, which connects with B, is sometimes provided with a blow-off cock that will admit of a discharge of the sediment. More commonly the piping is arranged as shown in Fig. 113, when sediment is removed by occasionally drawing water from the cock h.
Fig. 115.—Method of connecting the range boiler when placed on the floor below the heater.
Location of Range Boiler.
—It is sometimes desired to place the range boiler on a different floor, either above or below the range. While such arrangements are entirely possible the circulation of the water is not so good as that described above. The weight of the two columns of water in the connecting pipes are so nearly balanced that good circulation is not always possible. In Fig. 115 the connections are shown, where the tank is located in the basement. In connecting the water-back to the tank under such conditions the piping is relatively the same as is shown in the dotted connections of Fig. 113, but the connections are longer. The circulating pipe comes from the bottom of the tank and leads to the bottom of the water-back. The flow pipe from the top of the water-back is extended up to a distance equal or greater than the distance from the water-back to the bottom of the tank. The hot water is taken from the top of the flow pipe at any place above the tank.
Double Heater Connections.
—Two heaters are sometimes connected to one range boiler, each circuit being independent of the other. Under such conditions one or both heaters may be used. When the tank is connected as shown in Fig. 116 the pipe a, from the bottom of the tank, branches and leads to b and b´, at the bottom of each of the heaters. The flow pipes from the top of the heaters enter the tank at separate places, the lower heater sending its water into the side of the tank at c, and the upper heater flowing into the pipe d, at the top of the tank. It would be perfectly possible to reverse the connections for the flow pipes in the arrangement of Fig. 116 and attain the same results. In such combinations the heaters are sometimes piped tandem, the water flowing through each of the heaters in turn. This, however, is not the best method to employ, for if only one of the heaters is used the second acts to cool the water.
Fig. 116.—Double connections for the range boiler where a heater is placed in the basement for occasional use.