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PUMP SELECTION PROCEDURE <br /> A. Determine pump capacity: <br /> Gravity Distribution END PERFORATION OF A PERFORATED LATERAL <br /> 1. Minimum suggested is 600 gallons per hour(10 gpm)to stay ahead of �Grou cover <br /> water use rate. <br /> Topsoil <br /> 2. Maximum suggested for delivery to a drop box of a home system is 2,700 - - <br /> Layer of Geolexille Fabric(or lour- <br /> gallons per hour(45 gpm)to prevent build-up of pressure in drop box. Loomy Sand Layer arch layer of hay or Wow covered <br /> wdh red rosin paper) <br /> er' �or a veY"-`- Perleroti 11 orllled flonronloll <br /> Pressure Distribution tt' r"'' i!!' -into P flex <br /> 3. a. Select number of perforated laterals /�Plus AI Least 12.10 Edge r Top y <br /> �t Drain Field.Rocha -� ( of Rock Layer <br /> b. Select perforation spacing= ft. P..rurutlone Located at <br /> c. Subtract 2 ft.from the rock layer length. clean sand Layer Bottom of Lateral <br /> yet ngt -2 ft.= ft. <br /> OrI0lnal Soil Properly Seorified <br /> d. Determine the number of spaces between perforations. Before Placing Sand Layer <br /> Length perf.spacing= ft.+ ft.= spaces TABI.F.OF PERFORATION DISCFIARCES 1N GPM <br /> e. spaces+ 1 = perforations/lateral <br /> f. Multiply perforations per lateral by number of laterals to Head Perforation diameter(inches) <br /> get total number of perforations. - - <br /> - perforations. y7/32 ��' <br /> x <br /> s tent - <br /> 1.03 0.56 0.74 <br /> 0 0.69 1. <br /> g• <br /> X gpm. 2. b 0.80 04 <br /> pert, gpm?-pert= <br /> 2.5 0.89 1.17 <br /> 3.0 0.98 1.28 <br /> SELECTED PUMP CAPACITY gpm 4.0 1.13 1.47 <br /> 5.0 1 1.26 1.65 <br /> B.Determine head requirements: aUse 1.0 foot of head for residential systems. <br /> 1. Elevation difference between pump and point of discharge. bUse 2.0 feet of head for other establishments <br /> V feet <br /> 2. If pumping to a pressure distribution system,add five feet for pressure <br /> required at manifold S <br /> feet <br /> 3. Friction loss 1 Pipe Length <br /> a. Enter friction loss table with gpm and pipe diameter. r Point of Discharge <br /> Read friction loss in feet per 100 feet from table. <br /> F.L._ .S t ft./100 ft of pipe Difference <br /> b. Determine total pipe length from pump to discharge Ef___EIe,,aLion <br /> ump <br /> point. Add 25 percent to pipe length for fitting <br /> loss,or use a fitting loss chart. Equivalent pipe F-18b <br /> length-1.25 times pipe length= 1.5 inch 2.0 inch 3.0 inch <br /> 2 O x 1.25= ZZ, feet gpm Friction loss per 100 R of pipe <br /> c. Calculate total friction loss by multiplying 10 0.69 0.20 <br /> friction loss in ft/100 ft by equivalent pipe length. 12 0.96 0.28 <br /> Total friction loss= Z S" x �,.tr�"r +1(x)=I feet 14 1.28 0.38 <br /> 4. Total head required is the sum of elevation difference, 16 1.63 0.48 <br /> special head requirements,and total friction loss. 18 2.03 0.60 <br /> s <br /> l� �1 20 2.47 0.73 0.11 <br /> 43.73 1 1 0.16 <br /> + + 5.230.23 <br /> 1;11 <br /> 7.90 0.30 <br /> (1) (2) (30 40 11.07 2.64 0.39 <br /> 45 14.73 3.28 0.48 <br /> TOTAL HEAD -�feet 50 3.99 0.58 <br /> 55 4.76 0.70 <br /> 60 5.60 0.82 <br /> C. Pump selection <br /> 1. A pump must be selected to deliver at least 7 gpm (Step A) <br /> with at least_[(0I_ feet of total head (Step B). <br />