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PRESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> 1. Select number of perforated laterals 3 Quarter inch perforations spaced 0 3' 12 <br /> .9 of.rock <br /> 2. Select perforation spacing= 3 ft <br /> Perf Sizing 3/16"-1/4" <br /> 3. Since perforations should not be placed closer than 1 foot to Perf Spacng 1.5'-s' <br /> the edge of the rock layer(see diagram),subtract 2 feet from <br /> the rock layer length. E-4: Maximum allowable rwmber of 114-inch perbrahons <br /> per Word to guamntee<10%discharge vaddion <br /> D layer -2 ft = �ft perfordon <br /> 4. Determine the number of spaces between perforations. <br /> Divide the length(3)by perforation spacing(2)and round :t 1 Inch 1.25 Inch 1.5 inch 2.0 inch <br /> dQ=to nearest whole number. 2.5 8 14 18 28 <br /> Perforation spacing= ft+ w ft= 1.3 spaces 3.0 8 13 17 26 <br /> 5. Number of perforations is equal to one plus the number of 3.3 7 12 16 25 <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. 15.0 6 10 14 22 <br /> ) spaces+1 = perforations/lateral E-6: Perforation Discharge In gpm <br /> 6. A. Total number of perforations= perforations per lateral (5) perforation diameter <br /> times number of laterals (1) head inches <br /> perfs/lat x 3 at= L- Z _perforations (feet) 3/16 7/32 114 <br /> 1.00 0.42 0.56 0.74 <br /> B. Calculate the square footage per perforation. 2.0b 0.59 0.80 1.04 <br /> Should be 6-10 sgft/perf.Does not apply to at grades. <br /> Rock bed area= rock width(ft)x rock length(ft) 5.0 0.94 1.26 1.65 <br /> /0 ft x �ft= 1'V sgft ousel.o root r«s�r,g�e-ron,�N non,es. <br /> Square foot per perforation=Rock bed area+number of perfs (6) b use 2.0 feet for an in else. <br /> 10 sgft+____LJ7Z..perfs gft/perf MA,IFOL, LOCATED AT ENO OF PREMAE DISTRIBUTION 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 /> 11�-► �r4. Wt RSO.. <br /> F�Z perfs x 7 -I gpm/perfs= 3 I gpm <br /> 8. If laterals are connected to header pipe as shown on upper10 <br /> , <br /> example,to select minimum required lateral diameter;enter "° <br /> figure E-4 with perforation spacing(2)and number of perforations <br /> per lateral(5) Select minimum diameter for <br /> 4TOUT OF FEIIF°MTEp FN[UTERINE FOR <br /> perforated lateral= 11)-t. inches. "' "`° <br /> RN+M:r!L <br /> 9. If perforated lateral system is attached to manifold pipe near <br /> the center,lower diagram,perforated lateral length(3) and <br /> number of perforations per lateral (5)will be approximately one <br /> half of that in step 8. Using these values,select minimum <br /> diameter for perforated lateral= inches. <br /> OMC <br /> Of <br /> nRvi <br /> I hereby certify that I have completed this work in accordance with applicable ordinances, rules and laws. <br /> (signature) 2` (license#) - )'d 3 (date) <br />