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PRESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> 1. Select number of perforated lateralsQuarter inch perforations spaced. ®3' i2 <br /> 2. Select perforation spacing= 3 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 15-5' <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 perforaffons <br /> per lateral to guarantee<10%discharge variation <br /> o c =yer length -2 ft = �0 ft perforation <br /> 4. Determine the number of spaces between perforations. spacing <br /> feet 1 Inch 1.25 Inch 1.S inch 2.0 inch <br /> Divide the length(3)by perforation spacing(2) and round <br /> down to nearest whole number. <br /> 2.5 8 14 18 28 <br /> Perforation spacing= GO ft+ ft= ko spaces 3.0 8 13 17 26 <br /> � <br /> 5. Number of perforations is equal to one plus the number of 3.3 7 12 16 254.0 7 11 15 23 <br /> perforation spaces(4). Check figure E-4 to assure the number of 5.0 6 10 14 22 <br /> perforations per lateral guarantees <10% discharge variation. <br /> _ao spaces+1 = a 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�_lat= (®3 (feet) 3/16 7/32 1/4 perforations 1.00 0.42 0.56 0.74 <br /> B. Calculate the square footage per perforation. 2.0b 0.59 0L11 <br /> 80 1.04 <br /> Should be 6-10 sqft/perf.Does not apply to at-grades. <br /> Rock bed area = rock width (ft)x rock length(ft) 5.0 0.96 1.65 <br /> /O ft X (O-L- ft= (D'o1O Sqft a Use 1.0 foot e-family homes.Square foot per perforation=Rock bed area +number of perfs (6) b Use 2.0 feet nin else. <br /> (oPL0sgft+__p_7�_perfs =_2-.�sgft/pert <br /> SUUNFMD LOCATED AT END Or PRES"E DISTRIBUTION SMB <br /> 7. Determine'required flow rate by multiplying the total number of <br /> perforations (6A) by flow per perforation(see figure E-6) Zra <br /> (41> perfs x gpm/perfs=42-gpm <br /> 8. If laterals are connected to header pipe as shown on upper ; <br /> example,to select minimum required lateral diameter;enterWIVE <br /> �,,, '"` <br /> figure E-4 with perforation spacing (2) and number of perforations ��``d <br /> per lateral (5) Select-mini um diameter for <br /> uVou+Of rcWwno wtuTa•u nal <br /> perforated lateral= inches. FMWAE°I" "',N, <br /> "NN IN WUND <br /> .[MYMRO IWiK.K <br /> 9. If perforated lateral system is attached to manifold pipe nearIND <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= 0-6 inches. <br /> �Md <br /> I hereby certify that I have completed this work in accordance with applicable ordinances, rules and laws. <br /> ��� 7 (signature) (license#) _ 3-)f?-0!4_ (date) <br />