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Unlevel Pressure Distribution System Design - 10/25/04 <br /> 1. Lay out system in order of highest to lowest elevation <br /> Line 1 Elevation 997.9 ft Length 92 ft <br /> Line 2 Elevation 995.7 ft Length 92 ft <br /> Line 3 Elevatiqn ft Length ft <br /> Line 4 Elevati�n ft Length ft � <br /> Line 5 Elevation ft Length ft <br /> 2. Change in Elevation over the Trenches <br /> Highest elevation-lowest elevation: 997.9 - 995.7 = 2.2 feet <br /> 3. Total Head=head at orif'r�es(2ft)+change in elevation(2) 2 ft + 22 ft = 4.2 feet <br /> ("�f gneater than 5 feet modify design) <br /> 4. Calculate pressure head for each system <br /> 1. Highest Trench Elevation the Head=2 feet <br /> 2. Po+(E1 -Ex)=DEu <br /> Line�1 Elevation 997.9 2+ [E1 -E1]=2+[ 997.9 - 997.9 ]= 2.0 feet <br /> Line 2 Elevation 995.7 2+[E1 -E2]=2+[ 997.9 - 995.7 ]= 4.2 feet <br /> Line 3 Elevation 0.0 2+[E1 -E3]=2+ [ 997.9 - 0.0 ] = 0.0 feet <br /> Line 4 Elevation 0.0 2+[E1 -E4]=2+ [ 997.9 - 0.0 ]= 0.0 feet <br /> Line 5 Elevation 0.0 2+[E1 -E5]=2 + [ 997.9 - 0.0 ]= 0.0 feet <br /> 5. Determine flow rate per hole(See figure E-6) <br /> Line 1 Pres 2.0 Perf Diameter 7/32 = 0.80 gpm <br /> Line 2 Pres 4.2 Perf Diameter 7/32 = 1.18 gpm <br /> Line 3 Pres 0.0 Perf Diameter = gpm <br /> Line 4 Pres 0.0 Pert Diameter = gpm <br /> Line 5 Pres 0.0 Perf Diameter = gpm <br /> 6. Calculate flow for Line 1 <br /> Number of perforations- len th of pipe-2)/spacing]+1 <br /> [( 92 ft-2ft) / 3� ft]+1 = 31 perforations(Check figure E-4 to make sure it is ok) <br /> Flow= number of perforations x flow rate <br /> 31 pert x 0.80 gpm = 24.8 gpm <br /> 7. Calculate the gallons per foot for Line 1 <br /> Gallons/length= 24.8 gpm / 92 ft= 0.27 gpm/ft <br /> E� Perforation Dischar e in GPM E-4 Maximum Number of 1/4 inch perforations <br /> Pressure r lateral to uarantee<10%discha e variation <br /> Head Perforation Diameter in inches Perforation <br /> feet 1/8 3/16 7/32 1/4 Spacing <br /> 1 0.18 0.42 0.56 0.74 feet 1 inch 1.25 incl 1.5 inch 2.0 inch <br /> 1.5 0.22 0.51 0.68 0.90 2.5 8 14 18 28 <br /> 2 0.26 0.59 0.80 1.04 3.0 8 13 17 26 <br /> 2.5 0.29 0.65 0.88 1.17 3.3 7 12 16 25 <br /> 3 0.32 0.72 0.98 1.28 4.0 7 11 15 23 <br /> 4 0.37 0.83 1.13 1.47 5.0 6 10 14 22 <br /> 5 0.41 0.94 1.26 1.65 Page 1 of 2 <br />