ECONOMICAL USE OF FUEL IN CREAMERIES. 41 
the engine and other steam-driven units be shut down the reducing 
valve will open up and supply the full amount of steam required 
and at the pressure desired. 
In figure 12 there are shown, connected to the exhaust-steam main, 
a flash pasteurizer, a milk heater, and one radiator of the heating 
system. The steam pressure on these units is maintained constant 
automatically by the use of the back pressure and reducing valves as 
previously explained. The steam is delivered under water in the 
jacketed space surrounding the pasteurizer and is all condensed. 
The steam delivered to the disk milk heater is also condensed in the 
heater. The condensation from these two units is piped direct to the 
hot well, from which it is pumped by the boiler-feed pump to the 
boiler, thus utilizing a large portion of the heat in the water. The 
condensation is returned to a low-pressure steam trap, which also 
discharges to the hot well. The boiler- feed pump, however, should 
be placed within about 3 feet of the surface of the water in the hot 
well in order to handle the hot water satisfactorily. The temperature 
of the water in the hot well will be cooled down to a point at which 
the pump will handle it satisfactorily if placed 3 feet above its 
surface. 
The storage-water heater is connected to the exhaust receiver, as 
shown. A stop valve is placed in the pipe connecting the two so that 
the supply of exhaust steam may be entirely cut off if desired. Just 
after the stop valve a thermostatic valve is placed in the pipe supply- 
ing steam to the heater. The function of this valve is to maintain 
automatically a fixed temperature of the water in the heater. If the 
temperature of the water in the heater falls through supplying cold 
water the thermostatic valve will open and admit steam to the heater 
coils ; if on the other hand the temperature of the water rises to the 
point at which the thermostatic valve is set it will immediately cut 
off the steam supply. The capacity of the storage heater should be 
sufficient to keep on hand a large v6lume of hot water ready for in- 
stant use. A large volume of water also has the advantage of allow- 
ing the heat in the exhaust steam to be stored at a time when but 
little or no use is being made of it. The boiler- feed pump is so con- 
nected that it can draw from either the hot well or the storage heater 
as desired. 
In many creameries it is desirable to pasteurize milk and cream by 
the use of hot water instead of steam. Piping connections from the 
storage heater to a counter-current heater and pasteurizing vat are 
shown in the diagram, as well as hose connection for drawing off hot 
water for washing purposes. A circulating pump is shown con- 
nected to the pipe line in order to force the hot water through the 
system at a high velocit}^. When not using hot water for pasteuriz- 
ing the circulating pump may be stopped. As the hot-water piping 
