The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California

Hot Water Suply

12. A water front, exposed as it is, on only one side, to heat of varying intensity, is subjected to severe internal strains, and hence, for safety, the metal must be much thicker than is required merely to resist the water pressure.

Water fronts are usually designed for a test pressure, when cold, of 700 pounds per square inch; but in constant use they tend to become clogged with scale and are sometimes overheated and weakened. They should be inspected periodically and be replaced if their condition arouses doubt of their safety.

The capacity of a water front is measured by its heating surface, in square inches, considering only the side exposed to the fire. On an average, about 100 square inches of external heating surface in direct contact with the fire is sufficient for a 40-gallon tank.

Pipe coils frequently are used instead of castings of the type shown in Fig. 5, but the principle of application is the same with pipes as with a hollow box.

13. The method of heating domestic water by means of a water front is not to be recommended except in rural districts where no other means is available. It is not practicable, with this scheme, to control automatically the water temperature, which varies widely with the amount withdrawn and with the intensity of the fire.

The passageways through the parts of the water front exposed to the fire tend to clog rapidly; also, the presence, in the firebox of the stove or furnace, of the water-cooled surface of the water front reduces the efficiency of the combustion.