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PUM 3ELECTION PROCEDURE <br />1. Determine pump capacity: <br />A. Gravity Distribution <br />1. Minimum required discharge is 10 gpm <br />2. Maximum suggested discharge is 45 gpm <br />For other establishments at least 10% greater than the water <br />supply rate, but no faster than the rate at which effluent will flow <br />out of the distribution device. <br />B. Pressure Distribution -see pressure design worksheet <br />Selected Pump Capacity: 20 !gpm <br />2. Determine head requirements: <br />A. Elevation difference between pump and point of discharge. I 10 !feet <br />B. Special head requirement? (See Figure -Special Head Requirements) <br />I O !teet <br />C. Friction loss <br />1. Select pipe diameter 2 !in <br />2. Enter Figure E-9 with gpm (1A or B) and pipe diameter (C1) <br />Read friction loss in feet per 100 feet from Figure E-9 <br />Friction loss= I 15 !ft! 100 ft of pipe <br />3. Determine total pipe length from pump discharge to soil system discharge point. <br />Estimate by adding 25 percent to pipe length for fitting loss. <br />Equivalent pipe length times 1.25 = total pipe length I 0.73 !ftx 1.25 = 0.9125 feet <br />4. Calculate total friction loss by multiplying friction loss (C2) <br />by the equivalent pipe length (C3) and divide by 100. <br />FL= 15 ft/100ft X 0.9125 ft I 100= 0.1 <br />D. Total head requirement is the sum of elevation difference (A), special <br />head requirements (B), and total friction loss (C4). <br />10 ft + 0 ft + 0.1 ft <br />Total Head: 10.1 feet <br />3. Pump Selection <br />1. A pump must be selected to deliver at least 20 gpm (1A or B) <br />with at least 10.1 feet of total head (2D). <br />feet <br />soil treatment svstern <br />& point of discharge : : ::: :~:: ;; :: : : : : : <br />2/!.-. elevation <br />difference <br />Special Head Requirements <br />Gravity Distribution Oft <br />Pressure Distribution 5ft <br />E-9 Friction Loss in Plastic Pipe <br />per 100 ft <br />nominal <br />Flow Rate pipe diameter <br />gpm 1.5" 2.0" 3" <br />20 2.47 0.73 0.11 <br />25 3.73 1.11 0.16 <br />30 5.23 1.55 0.23 <br />35 6.96 2.06 0.3 <br />40 8.91 2.64 0.39 <br />45 11.07 3.28 0.48 <br />50 13.46 3.99 0.58 <br />55 4.76 0.7 <br />60 5.6 0.82 <br />65 6.48 0.95 <br />70 7.44 1.09 <br />Page 1 of 1