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� PRESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> 1., Select number of perforated laterals 3 uarter inch erforations s aced�3' 12 <br /> • 9"of rock <br /> 2. Select perforation spacing= 3.0 ft <br /> Perf Sizing 3/16"-1/4" <br /> 3. Since perforations should not be placed closer than 1 foot to Perf Spacutg 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 number ot 1/4-inch perforations <br /> �� per lateral to guarantee<1090 discharge variation <br /> Roc ayer eng �2 f t —�ft perforation <br /> 4. Determine the number of spaces between perforations. spacing <br /> feet 1 inch 1.25 inch 1.5 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 = l�c- ft= ? ft= �� spaces 3.0 8 13 17 26 <br /> 3.3 7 12 16 25 <br /> 5. Number of perforations is equal to one plus the number of 4� � �� 15 23 <br /> perforation spaces(4). Check figure E-4 to assure the number of <br /> perforations per lateral guarantees <10% discharge variation. 5.0 6 10 14 22 <br /> �a-. spaces + 1 = a? perforations/lateral E-6: Pertoration 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—��perforations (feet) 3/16 7/32 1/4 <br /> 1.Oa 0.42 �56 0.74 <br /> �- <br /> B. Calculate the square footage per perforation. 2,0b 0.59 0.80 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 0.94 1.26 1.65 <br /> JD ft x (e� ft = (o�� SC�ft ° Use 1.0 foot for sfngle-fomily homes. <br /> Square foot per perforation = Rock bed area =number of perfs (6) b Use 2.0 feet for on n�� else. <br /> ���_.l sqft=�perfs = �.� sqft/perf MANIFOID LOCATED AT ENO OF PRESSURE DISTFIBUTION 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 /> �perfs x .5�o gpm/perfs =.��gpm '"�'°" <br /> 8. If laterals are connected to header pipe as shown on upper �,,,,�°�'-� <br /> 4i��waT[—� <br /> example, to select minimum required lateral diameter;enter ,,��'"` '�"�'""� <br /> figure E-4 with perforation spacing (2) and number of perforations ��`"`M <br /> per lateral (5) Select minimum diameter for <br /> uroo.w renraurco•�rc urc�.�s ron <br /> perforated lateral= inches. .pEgS,�E o,sip,.�t��, W MOUND <br /> �rcrauno n.snc rrc <br /> y. if perforated lateral system is attacnea to maniro�a pipe near `L,�„�,,,,��,,,• ,�,„�� <br /> the center,lower diagram,perforated lateral length (3) and � '�"�°":�"�;`�;`� .. �""`� <br /> Y�nao <br /> number of perforations per lateral (�)will be approximately one ,�.��.;�,�,�.,,,�,„ •�n <br /> half of that in step 8. Using these values,select minimum '°• '- <br /> diameter for perforated lateral = '�_inches. � `���`�"� <br /> ..��.. a u�„� <br /> � <br /> ,��*to rr..- <br /> d K .v+� � <br /> ����TM <br /> I hereby certify that I have completed this w�ork in accordance with applicable ordinances, rules and laws. <br /> �� L7"� � � (sigr►ature) 3�y (license#) a- ►y —t7 I (date) <br />