The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Hot Water Suply
Such an arrangement permits cutting out any one of the coils for cleaning or repair while the other coils may continue to function. This may be accomplished by closing the valves d and d' installed in the connecting pipes between the manifolds and the storage tank, then disconnect the unions that join any coil to the headers, plug them and put the heater back into service. In addition to the valves d and d', a pressure-relief valve e is provided to prevent excessive water pressure should the gas be ignited when the valves d and d' are closed. The hot water flow pipes from the tank to the house system are shown at / and f. Pipe g admits cold city water to the tank. The gas main enters the heater through the pipe h, flowing through a temperature-control valve i, which responds to changes in water temperature, thereby regulating the gas supply to the safety-control diaphragm valve j in the gas main to the heater. The small pipe k is a gas pipe running to the escapement burner in the heater so as to dispose of the small amount of gas which is used intermittently in operating the thermostat i. The valve j is the main safety control and is provided with a small escapement pipe l leading to the hood or chimney m. If the pilot flame in the boiler should be extinguished, the gas pressure will cause the valve j to close.
The doors opening through the front casing of the boiler have spring hinges so arranged that the remotely possible minor explosion that may occur inside the device when the gas- burning rate is increased, will be relieved. Gas-burning boilers often are made of cast-iron sections assembled with nipples, like radiators or heating boilers. They have some advantages in that each section may have its own gas burner, thus permitting a wide range of flexibility in the size of heater and in the number of burner sections in use at any one time.
22. Oil-Fired Water Heaters.—Oil-fired water heaters are essentially like gas-fired ones, except that with oil the combustion chambers and passages for the products of combustion must be larger than those for gas, so as to permit completion of chemical reactions before chilling the fire, and also to allow for inspection and cleaning, which, in the case of oil fuel, necessarily will be at far more frequent intervals than with gas.
Oil-fired domestic water heaters are available from many manufacturers, in automatic self-contained, heavily insulated units, usually burning the lighter oils, such as No. 1, with electrically operated atomizers. For rural districts where electric energy is not available, oil-burning domestic water heaters of one-family capacity are obtainable.
