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PRESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> 1. Select number of perforated laterals 3r �F.,��[;..inch in <br /> r <br /> Quarte <br /> ---- - '-cu Rarj' <br /> 2. Select perforation spacing= 3.0ft s'.of rock <br /> 3. Since perforations should not be placed closer than 1 foot to Perf Sizing Perf Spacing <br /> s8 i.s, s' /4" <br /> the edge of the rock layer (see diagram),subtract 2 feet from <br /> the rock layer length. <br /> E-4: Maximum allowable number of 1/4-inch perforations <br /> SS ft per lateral to guarantee<10%discharge variation <br /> oc ayer ng -2 ft = 3 <br /> Perforation <br /> 4. Determine the number of spaces between perforations. spacing <br /> Divide the length(3)by perforation spacing(2) and round feel 1 inch 1.25 inch :1.5nch 2.0 inchd wn to nearest whole number. <br /> 2.5 8 14 28 <br /> Perforation spacing=_ S 3 ft-i- 3 ft=-L2-spaces 3.0 8 13 <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 /> spaces + 1 = l i perforations/lateral ra <br /> 6: Perforation Discharge in <br /> g gpm <br /> 6. A. Total number of perforations = perforations per lateral (5) head times number of laterals (1) perforation diameter <br /> inches <br /> .J� "'-perfs/lat x lat=�-perforations eet) 3/16 7/32 __114 <br /> B. Calculate the square footage per perforation. 1.0o 0.42 0.560.74 <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 1 0.941 1.26 1.65 <br /> _Lo ft x­S _ft= SUi sgft <br /> Square foot per perforation = Rock bed area +number of perfs (6) b use 2.0 feet for anything e,enomes. <br /> 660 sgft= 5� _perfs = �,.�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 /> ^K <br /> - <br /> .59 perfs x [� gpm/perfs =__4_Q_gpm i <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 perforationsOF <br /> per lateral (5) Select minimum diameter for <br /> / <br /> Perforated lateral= /� LAYOUT Oi PERrORATEO PIPE LATERALS FOR <br /> AA les. PRESSURE OISTRISUTION W MOUND <br /> 9. KINDIMT[0 RAbTIt iP[ <br /> If perforated lateral system is attached to manifold pipe near <br /> [ oRoloN[wTRo H• y,cW[ <br /> the center,lower diagram,perforated lateral length (3) and `"° tOA"ti`t~` =` ''°" <br /> V w <br /> number of perforations per lateral (5)will be approximately oneKAi AT. <br /> .,, r"°�° <br /> half of that in step 8. Using these values,select minimum b '"` d <br /> diameter for perforated lateral = inches. <br /> [ b, <br /> ![ ATE°L'KR,L <br /> f "' ^"^ <br /> �LLRSTP R <br /> I hereby certify that I ha a completed this work in accordance with applicable ordinances, rules and laws. <br /> (signature) `I (license 0 (date) <br />