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Name: Chadwick
Status: Student
Age: 16
Location: N/A
Country: N/A
Date: N/A

I would like to know how to calculate the water pressure for gravity fed water supply systems. I am doing a 4-H club project on supplying water to livestock from a water storage tank.

What is the formula for calculating the output pressure of a tank given the factors of tank size and elevation and the size of the output pipe?

It's really easy. If the vertical distance between the spigot and the surface of the water is H inches, and you want the pressure in pounds per square inch, you just calculate the weight in pounds of a column of water one inch square by H inches high. The size of the output pipe does matter a little, because causes a pressure drop, but at the water speeds you're interested in the effect is small unless the pipe is very narrow or very long. A garden hose, for example, doesn't produce much of a pressure drop at household water pressures.

Tim Mooney

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