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PUMP SELECTION PROCEDURE <br />_A. Determine pump capacity: <br />Gravity Distribution · · · · · <br />1. Minimum suggested is 600 gallons per hour (10 gpm) to stay ahead of <br />water use rate. <br />2. Maximum suggested for delivery to a drop box of a home system is 2,700 <br />gallons per hour (45 gpm) to prevent build-up of pressure in drop box. <br />Pressure Distribution <br />3. a. Select number of perforated laterals ____ _ <br />b. Select perforation spacing= ____ ft. <br />c. Subtract 2 ft from the rock layer length. <br />ltxir.liyc,>cngh -2 ft.= __ .ft. <br />• d. Determine the number of spaces between perforations. <br />Length perf. spacing = __ ft. <br />1 <br />+ __ ft. = __ spaces <br />e. ___ spaces+ 1 = ___ perf9rations/lateral <br />f. Multiply perforations per lateral by number of l<1terals to <br />get total number of perforations. <br />r;;;r. x p«>a1t.....il = __ perforations. <br />g, -;;;: X &J'"'lpen =--gpm. <br />SELECTED PUMP CAP AOTY 4-5' gpm <br />B. Determine head requirements: <br />1. Elevation difference between pump and point of discharge. <br />'2-5 feet <br />2. If pumping to a pressure distribution system, add five feet for pressure <br />~uired at manifold _5 __ feet <br />3. Friction loss <br />a. Enter friction loss table with gpm and pipe diameter. <br />ENO ?€RFORATlON Cf= A PERFORATED LATERAL <br />• ·. ,U 1.-IX' IO Edqt <br />?:"',=;,-;~~~~,....,._....._..,:.:,..,.~·:;;.:o'' ol RDdl. L.oyc, .... ~ • ............... ... <br />Pfl'lotoUOM LDc:11-0 al <br />8011°""9 °" 1..At ■rc.a <br />'½?:~·~,; ;~.:;~··::,;~~ :. <br />Belon Plodnt S4noi t..,.,... <br />TABLE OF PERFORApON DISCHARGES IN GPM <br />Head Perforation diameter (inches} <br />'I,. 'I. <br />1.0a D.56 0.74 <br />1.5 0.69 0.90 <br />2.Db 0.80 1.04 <br />2.5 0.89 1.17 <br />3.0 0.98 1.28 <br />4.0 1.13 1.47 <br />5.0 1.26 1.65 <br />a Use 1.0 foot o{ head for residential systems. <br />bUse 2.0 feet of head for other establishments <br />Pipe Length <br />Point of Discharge <br />Read friction loss in feet per 100 feet from table. · <br />F.L = 5, 2-'D. ft./100 ft of pipe · <br />· b. Determine total pipe length from pump to discharge <br />point. Add 25 percent to.pipe length for fitting <br />□ Ele-va_u_· o_n_D_i_E_e., e•,,•«r . <br />. Pump <br />4. <br />loss, or use a fitting.loss chart. Equivalent pipe <br />· --length-1.25 times pipe length= ·· <br />~ x 1.zs = Zs:z:> feet <br />c. Caiculate total friction loss by multiplying <br />friction loss in ft/100 ft by equivalent pipe length. c2 <br />Totalfrictionloss= -ZSc> x 7.ZS +100= _ _,~""'---.feet' · <br />. Total head required is the sum of elevation difference, <br />special head requirements, and total friction loss. <br />-Z5 _____ ;._..._+ ·£-~ ~ <br />(1) (2) (3d <br />TOTAL HEAD ·2 feet <br />C. Pump selection . . <br />l. A pump must be selected to deliver at least ~ gpm (Step A) <br />·with at least ;g' feet of total head (?tep B). <br />gpm <br />10 <br />12 <br />14 <br />16 <br />18 <br />20 <br />25 <br />30 <br />35 <br />40 <br />45 <br />50 <br />55 <br />60 <br />F-18b <br />1.5 inch. · 2.0 inch 3.0 inch <br />Frictlcc Lea per 1001't o( pipo <br />0.69 0.20 <br />0.96 0.28 <br />1.2& 0.38 <br />1.63 0.48 <br />2.03 0.60 <br />2.47 0.73 0.11 <br />3.73 1.11 0.16 <br />· 5.23 1.55 0.23 <br />7.90 2.06 0.30 <br />11.07 2.64 0.39 <br />14.73 3.28 : 0.48 <br />3.99--·o.58 <br />4.76 0.70 <br />5.60 0.82