Originally Posted by Daniel Holzman
Gary, the formula you posted The weight of a column of water is figured at .433 psi times the height
is for the pressure of the water in pounds per square inch, NOT the weight of the water. The weight of a column of water is simply the volume of the column of water times the unit weight of water, which is 62.4 pounds per cubic foot in English units. To compute the voume of water in a pipe, you take the area of the pipe times the height of the water.
A 4 inch ID pipe has an area of approximately 0.09 square feet, so 15 feet of water in the pipe would weight .09 * 15 * 62.4 = 80 lbs +/-
Dan, that has nothing to do with what we were talking about.
We where talking about calculating TDH (total dynamic head) and you don't use the "weight" of the water the way you explain it or how Chris thought he had to. And you should know that.
I told him how to convert the "weight" to psi in terms meant to be easy for him to understand; .433 times the height of the column of water to the highest fixture in the system is part of the TDH calculation.