Errata

Camping Magazine, Nov-Dec, 2002

The Building Principles column on this topic in the September/October issue on page 58, reflected an error in calculations. The calculations should read as follows:

The first and simplest method of supplying pressure is gravity The well pump moves the water from underground to a storage tank whose height has been set to deliver a regular, reliable system pressure. For each 1 pound of pressure required, the water needs to be raised about 2.31'. Put another way raising the water I 'increases the pressure 0.43 pounds per square inch (psi). Average system pressure range at a faucet or showerhead should be between 30 and 50 psi. This means that the lowest water level above the highest faucet has to be at least 30 psi * 2.31 = 69.3' above the highest faucet.

The upper end of the operating range is calculated the same way: 50 * 2.31 = 115.5' above the highest faucet.

Another way of looking at this is that the fluctuating height of the water in the tank ("operating range") is about 115.5' - 69.3' = 46.2'.

At the bottom of that same page the cent ([cents]) symbol was inadvertently used when the word "diameter" should have been indicated.