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9 <br /> PUMP SELECTION PROCEDURE <br /> A. Determine pump capacity: <br /> Gravity Distribution <br /> 1. Minimum suggested is 20 gpm <br /> 2. Maximum suggested is 45 gpm Perforation Discharges in GPM <br /> Pressure Distibution Head Perforation diameter <br /> feet inches <br /> 3.a. Select number of perforated laterals 7/32 1/4 <br /> b. Select perforation spacing= feet. 1.0a 0.56 0.74 <br /> C. Subtract 2 ft. from the rock layer length. 1.5 0.69 0.90 <br /> Rock layer length <br /> -2 ft. = feet. 2.Ob 0.80 1.04 <br /> d. Determine the number of spaces between perforations. a Use 1.0 foot single homes. <br /> Length perf.spacing= ft.-1- ft.= spaces <br /> b Use 2.0 feet for anything else. <br /> e. spaces+1 = perforations/lateral <br /> f. Multiply perforations per lateral by number of laterals to <br /> get total number of perforations. rrar x per S, era = perforations. <br /> g. T Mr X gpm ,,er = gpm. <br /> SELECTED PUMP CAPACITY gpm <br /> B.Determine head requirements: <br /> 1. Elevation difference between pump and point of discharge. <br /> /O feet <br /> 2. If pumping to a pressure distribution system,five feet for pressure Soil ceaunentsystem <br /> required at manifold if gravity system,zero. °•°=" <br /> a,' feet Total pipe length <br /> 3. Friction loss <br /> a. Enter friction loss table with gpm and pipe diameter. we oNa,ar,Ddfffef <br /> Read friction loss in feet per 100 feet from table(F-14). pig <br /> ------- -- - <br /> F.L._z o ry ft./100 ft of pipe <br /> ---- <br /> b. Determine total pipe length from pump to discharge <br /> point. Estimate by adding 25 percent to pipe length for fitting <br /> loss,or use a fitting loss chart(F-15 feet). <br /> Equivalent pipe length-1.25 times pipe length= <br /> .ZPU x 1.25= ZcSO feet Friction Loss in Plastic Pipe <br /> c. Calculate total friction loss by multiplying <br /> friction loss in ft/100 ft by equivalent pipe length. Nominal <br /> pipe dia. <br /> Total friction loss= Z-%S'O x Z.D(=100=-S feet How Rate <br /> 4. Total head required is the sum of elevation difference, gpm 1.5" 2" 3" <br /> special head requirements,and total friction loss. <br /> /D 20 2.47 0.73 0.11 <br /> + <br /> �I + %S 25 3.73 1.11 0.16 <br /> (1) (2) (30 30 5.23 1.55 0.23 <br /> 6.96 0.30 <br /> o 8.91 0.39 <br /> TOTAL HEAD Zd feet 45 11.07 3.28 0.48 <br /> 50 13.46 3.99 0.58 <br /> C. Pump selection 60 5.60 0.82 <br /> 65 6.48 0.95 <br /> 70 7.44 1 1.09 <br /> 1. A pump must be selected to deliver at least <br /> gpm (Step A) with at least,Zo feet of total head (Step B). <br />