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i <br /> ' PRESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> 1. Select number of perforated laterals 3 _ 12 <br /> 2. Select perforatio spacing= 3.0 ftQf,rock <br /> Perf Sizing 3/16"-1/4" <br /> • <br /> 3. Since perforationshould not be placed closer than 1 foot to Perf Spacing 1.5'-5' <br /> the edge of the r k layer(see diagram),subtract 2 feet from <br /> the rock layer length. E-4:•Maximum allowable number of 1/4-inch perforations <br /> 0,,,p0 ' per laterd to guarantee<10%discharge variation ' <br /> Rock yer length -2 ft = ft perforation <br /> 4. Determine the number of spaces between perforations. spacing <br /> Divide the length (3)by perforation spacing(2)and round fleet) 1 inch 1.25 inch 1.5 inch 2.0)rlctl <br /> down to nearest whole number. <br /> 2.5 8 14 18 28 <br /> Perforation spacing= 3$ ft+ 2a ft= IS-. spaces 3.0 8 13 17 26 <br /> 5. Number of perforations is equal to one plus the number of 3.3 7 12 165 <br /> perforation spaces(4). Check figure E-4 to assure the number of 4'0 7 11 15 23 <br /> perforations per lateral guarantees<10%discharge variation. 5.0 6 10 14 �2 <br /> 1 <br /> 11_ spaces + 1 = 13 perforations/lateral E-6: Perforation Discharge in gpml <br /> 6. A. Total number of perforations = perforations per lateral (5) perforation diamet+r <br /> times number of laterals (1) head (inches) ; <br /> 1°'' perfs/lat x �� tat= A3 (feet) 3/16 7/32 1/4 1 <br /> perforations <br /> 1.00 0.42 0.56 0.74! <br /> B. Calculate the square footage per perforation. <br /> Should be 6-10 sqft/perf. Does not apply to at grades. 2 0' 0.59 0.80 1.04; <br /> Rock bed area = rock width (ft)x rock length(ft) 5.0 0.94 1.26 1.651 <br /> /0 ft x ,r) ft= 3')U sqft <br /> ° <br /> Use 1.0 foot for single-family homes. <br /> Square foot per perforation =Rock be9rea+number of perfs (6) b Use 2.0 feet for anything else. <br /> 3 Q c) sqft+ 7.)'" perfs= c)•J sqft/perf <br /> ,...w01.0 LOCATED AT END OF PRESSURE DISTRIBUTION i SYSTEM <br /> 7. Determine required flow rate by multiplying the total number of <br /> perforations (6A) by flow per perforation(see figure E-6) <br /> 3 °I perfs 9C , ')Li gpm/perfs= o.t gpm tire.,a <br /> 8. If laterals are connected to header pipe as shown on upper . " <br /> example,to select minimum required lateral diameter;enter ,,,, °ore* l ws^" <br /> figure E-4 with perforation spacing (2)and number of perforations \,- ."`"" <br /> per lateral (5) Select minimum diameter for <br /> SIP(wEA EoN LP.Tlzts <br /> ..lEPerforated lateral= Z.- inches. <br /> R .II.IEO RAMC Pre <br /> 9. If perforated lateral system is attached to manifold pipe near �,�.I,,,,,,,,�„�,>r <br /> the center,lower diagram,perforated lateral length(3) and Y})` K"°""� <br /> number of perforations per lateral(5)will be approximately one ...ram ,.,,,,,. Fra. <br /> � <br /> half of that in step 8. Using these values,select minimum ``. _ <br /> diameter for perforated lateral= l <br /> inches. 'e'!' `^="I <br /> [InW a <br /> I <br /> P,.... 40. P,II <br /> \S .tE <br /> I he eby certify that I have corn leted this work in accordance with applicable ordinances, rules and laws. <br /> 41, Oil 4/:.7 <br /> (signature) 3"r Li. (license#) `d-)?,.'2010(date) <br />