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PRESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> L <br /> 1. Select number of perforated laterals Quarter inch Porforations spaced 3' 12" <br /> 2. Select perforation spacing= 3.o ft s of-rock <br /> Perf Sizing 3/16"-1/4" <br /> 3. Since perforations should not be placed closer than 1 foot to Perf Spacing 1.5'-5' <br /> the edge of the rock layer (see diagram),subtract 2 feet from <br /> the rock layer length. E-4: Maximum allowable number of 1/4-Inch perforations <br /> -2 ft = 5 3it per lateral to guarantee<10%discharge variation <br /> c <br /> o layer en perforation <br /> 4. Determine the number of spaces between perforations. spacing <br /> Divide the length (3)by perforation spacing(2)and round feet 1 Inch .1.25 Inch 1.5 Inch 2.0 inch <br /> down to nearest whole number. <br /> 2:5 8 14 18 28 <br /> Perforation spacing= 5i, ft+ 3 ft= ? spaces 3.0 8 13 18 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. 5.0 6 10 14 22 <br /> 17 spaces+ 1 = 1 4 perforations/lateral E-6: Perforation Discharge to gpm <br /> 6. A. Total number of perforations = perforations per lateral (5) perforation diameter <br /> times number of laterals (1) head Inches <br /> I erfs/lat x `? lat= (feet) 3/16 7/32 114 <br /> -�P ,�perforations <br /> J <br /> B. Calculate the square footage per perforation. 1.Oa 0.42 0.56 0.74 <br /> Should be 6-10 sqft/perf. Does not apply to at-grades. 2.0b 0.59 0.80 1.04 <br /> Rock bed area = rock width (ft)x rock length(ft) 5.0 0.94 1 1.26 1 1.65 <br /> 0 ft x SJ ft=__L5-Dsgft o use 1.0 foot for single-family homes. <br /> Square foot per perforation=Rock bed area +number of perfs (6) b Use 2.0 feet for anything else. <br /> fo _sgft+ perfs = 0- -2 sgft/perf <br /> MANIFOLD LOCATED AT END OF PRESSURE 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 /> WhK <br /> L� perfs x_,_'L1i_gpm/perfs= LgpIn h � <br /> 8. If laterals are connected to header pipe as shown on upper <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 /> perforated lateral= LAYOUT Dr REMDRATED RIPE LATERALS FOR <br /> inches.LeJ. MLSfVIIE D1STR1/Vito/ W MOVNO <br /> PX I TLD"TIC 0/1 <br /> 9. If perforated lateral system is attached to manifold pipe near __ <br /> the center,lower diagram,perforated lateral length(3) and VIA"'��gRW N ,,Woo <br /> r- o <br /> , <br /> num er of perforations per lateral (5)will be approximately one .LR, .As ,a L"T"""„ <br /> half of that in step 8. Using these values,select minimum b �- <br /> diameter for perforated lateral = I )a_ inches. "°� <br /> 9-W a <br /> �ATLOOF <br /> L�E,IL <br /> -K <br /> 1 hereby certify that I have completed this work in accordance with applicable ordinances, rules and laws. <br /> (signature) 3") � (license#) 7-oZl-5 <br /> (date) <br />