Re: Fuel pressure
David J. Gall
Sorry, Pat, I should have said 0.026 >PSI< per inch of height.
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Longwinded explanation follows: 0.026 psi per inch of height. That's pounds per square inch (pressure) per inch of height of the column. If you put two of my described columns sidebyside you'll have 12 lbs of fuel pushing down on 2 sq inches of surface area, again for a total pressure of 0.026 psi per inch of column height (231 inches height). Another way to say that is that the weight of a single CUBIC inch of fuel is 0.026 lbs. If you have a 3/8" I.D. fuel line, then your total weight of fuel in the line would be 3.14 x (3/8in)^2 x 0.026 psi per inch x inches of height. Note that psi per inch equals lbs per cubic inch: lbs/(in)^2/in = lbs/(in)^3. Note also that the result of that calculation will give you pounds, not psi, since (3/8in)^2 x inches of column height gives in^3 (volume) and wieght per volume times volume yields weight. That would be the pounds of weight of that particular column of fuel but not its pressure at the bottom of the column. The weight of the column divided by the square inches of the base of the column, in this case, the crosssectional area of the fuel line, 3.14 x (3/8in)^2, gives the pressure. But, notice that we've multiplied and then divided by that cross sectional area during the course of all this figuring. Those steps cancel each other out; Just leave out those extraneous steps and the simple calculation is left: 0.026 psi per inch of column height times column height gives pressure.... Ta da! Thanks for checking my work. David J. Gall
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