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9 <br /> PUMP SELECTION PROCEDURE <br /> k. 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-2 ft. = feet. <br /> 2.0b 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.+ ft.= spaces 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. rrm5 x __r_r,I= perforations. <br /> g. <br /> wig <br /> x gcm,pert = gpm. <br /> SELECTED PUMP CAPACITY 7 gpm <br /> B.Determine head requirements: <br /> 1. Elevation difference between pump and point of discharge. <br /> /0 feet <br /> 2. If pumping to a pressure distribution system,five feet for pressure system <br /> required at manifold if gravity system,zero. N <br /> cS� <br /> feet Total pipe length <br /> 3. Friction loss <br /> a. Enter friction loss table with gpm and pipe diameter. we a Elevation rhfference <br /> Read friction loss in feet per 100 feet from table(F-14). P'Pe 5 <br /> F.L.= 3.99 ft./100 ft of pipe 1. <br /> b. Determine total pipe length from pump to discharge I <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 /> 30 x 1.25= 3 7 Vs. feet Friction Loss in Plastic Pipe <br /> c. Calculate total friction loss by multiplying Nominal <br /> friction loss in ft/100 ft by equivalent pipe length. �/ pipe dia. <br /> Total friction loss= 3.9 9 x 3 7'PZ. =100= / Z feet <br /> 4. Total head required is the sum of elevation difference, F1 ow Ra <br /> to 1.5" 2" 3" <br /> special head requirements,and total friction loss. <br /> J o + '6.- + / /z 20 2.47 0.730.11 <br /> 25 3.73 1.1111 0.16 <br /> (1) (2) (3c) 30 5.23 1.55 0.23 <br /> 35 6.96 2.06 0.30 <br /> 40 8.91 2.64 0.39 <br /> TOTAL HEAD /(j c-feet 45 11.07 3.28 0.48 <br /> 50 13.46 3.99 0.58 <br /> 55 4.76 0.70 <br /> C. Pump selection 60 5.60 0.82 <br /> 65 6.48 0.95 <br /> 70 7.44 1.09 <br /> • <br /> ,/ 1. A pump must be selected to deliver at least <br /> `77 gpm (Step A) with at least IGPZ feet of total head (Step B). <br />