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 heater this is generally run directly into the heater and sprayed through the current of exhaust steam. It is for the control of this cold-water supply that the governor, E, is provided. In this case the governor on the cold-water supply should be set for a level of water a few inches below the level which operates the feed pump. Otherwise the cold water might be let into the heater while the pump was running and when it was not needed. The open heater should in all cases be provided with an overflow connected to a low-pressure trap. This outlet should be a few inches above the water-line, but should be low enough to prevent the possibility of a sudden inflow of return water flooding the exhaust pipes.

Steam Heating and Ventilation - Figure 8.png

Figure 8—Arrangement with Open Heater. With the arrangement shown in Figure 7 the cold water may be supplied by a pipe running direct to the receiving tank, and it may be regulated by hand, according to the level of the water, shown by the gauge glass, or by a float governor similar to the one indicated on the open heater in Figure 8.

In large plants also there are frequently two or more feed pumps, one of which has a suction connected to the cold-water supply, or the boilers are provided with injectors. Further details of piping will be discussed in a subsequent chapter.

It will be seen that, in connection with the open heater, the