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PRESSURE DISTRIBUTION SYSTEM Geotextile fabric ` .:r:,i::+, 'i-;�,=•pr:-.-,--;-•-:=t.:�.:=-p•;+-;i.�_rtri.`sYr_t'. :r- 1. Select number of perforated laterals 3Quarter inch perforations spaced 0 3' ._ :. ; " of rocs 2. Select perforation spacing= 3 .0 ft , ' Perf S 3/16"-1/4" 3. Since perforations should not be placed closer than 1 foot to Perf Spadng 1.5'-5' the edge of the rock layer(see diagram),subtract 2 feet from the rock layer length. E-4: Madman dawdle number of 1/4•Mch perforations per laterd to guarantee<10%discharge variation Rock n -2 ft = (.4 ft perforation s1uW 4. Determine the number of spaces between perforations. (feet) 1 Inch 125 Inch 1.1inch 2.0 inch Divide the length(3)by perforation spacing(2)and round down to nearest whole number. 2:5 8 14 18 28 Perforation spacing= (.00 ft+ 3 ft= 10 spaces 3.0 8 13 17 26 3.3 7 12 16 ° 25 5. Number of perforations is equal to one plus the number of 4.0 7 11 15 23 perforation spaces(4). Check figure E-4 to assure the number of 5.0 6 10 14 22 perforations per lateral guarantees <10%discharge variation. - a 0 spaces+1 = a) perforations/lateral E-6: Perforation Discharge in gpm 6. A. Total number of perforations= perforations per lateral(5) perforation diameter times number of laterals(1) head inches) (feet) 3/16 7/32 1/4 _ a t perfs/lat x 3 lat= (03 perforations 1.00 0.42 0.56 s.74 B. Calculate the square footage per perforation. 2,0b 0.59 0.80 1.04 Should be 6-10 sqft/perf.Does not apply to at grades. Rock bed area= rock width(ft)x rock length(ft) 5.0 0.94 1.26 1.65 /o ft x (.Z ft= 1.• ,0 sqft o Use 1.0 foot for single-family homes. Square foot per perforation=Rock bed area+number of perfs (6) b Use 2.0 feet for onvthInp else. (oma sqft+ (03 perfs= g•c sqft/perf MANIFOLD LOCATED AT END OF PRESSURE DISTRIBUTION SYSTEM 7. Determine required flow rate by multiplying the total number of perforations(6A).by flow per perforation'(see figure E-6) JO perfs x •14. gpm/pperfs= 47 . gpm imm- 8. If laterals are connected to header pipe as shown on uppervol .,.c example,to select minimum required lateral diameter;enter ��,M,�'"° figure E-4 with perforation spacing(2)and number of perforations \,/ per lateral(5) Select minimum diameter for LAYOUT a KII�pMTtB nnL FOR perforated lateral= inches. mi.MISTMMNTION IN PAWKY P.a Ramie Pot 9. If perforated lateral system is attached to manifold pipe near44 . •o,,,,, the center,lower diagram,perforated lateral length(3) and IND �` �'' • " „tp number of perforations per lateral(5)will be approximately one .- ;yr, ••••�•. half of that in step 8. Using these values,select minimum .-,e.=.e,,µ„ diameter for perforated lateral= a•0 inches. •.. M n`P' I hereby certify that I have completed this work in accordance with applicable ordinances, rules and laws. ' 5.-&-4•�� (signature) 3''74 (license#) (o-14-03' (date)