Approximately what is the pressure, in psig, on the bottom of a 10-ft, flat bottom, open tank filled to 100 percent of capacity with a fluid that has a specific gravity of 1.1?
The correct answer is B, 4.76 psig. A column of water exerts a pressure on the bottom of the tank according to the formula below. The level at 100 percent will be 10 feet.
PSI = [height in feet × SG] / 2.31 feet/psi
= [10 feet x 1.1] / 2.31
= 4.76 psi
Reference: Goettsche, L. D. (Editor), Maintenance of Instruments and Systems, Second Edition, ISA, 2005.
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