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i <br /> , ; <br /> ! PI7�ESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> 1. lect numlyer of perforated laterals 3. O arter inch erforations, aced�3' 12� <br /> :� 9'of,rock . . <br /> 2. lect perforation spacing= 3. c� ft � <br /> Perf Sizing 3/16"-1/4" <br /> 3. ince perforations should not be placed closer than 1 foot to Perf Spacing l.s'-s� <br /> e edge of the rock layer(see diagram),subtract 2 feet from <br /> e rock layer length. E-4: Maximum anowable number of 1/4-inch perforafions <br /> i �,� per lateral to guarantee<l OX d(scharge vcdation <br /> j ye: ng -2 f t =�_f t <br /> ' p6tI0IdlfOfl <br /> apacing <br /> 4. etermine the number of spaces between perforations. feet 1 inch 1.25 inch 1.5 inch 2.0 inch <br /> �ivide the length(3)by perforation spacing(2)and round <br /> �w to nearest whole number. 2,5 8 la 18 28 <br /> Perfor�tion spacing= � ft+ 3.o ft= �� spaces 3.0 8 13 �17� 26 <br /> 5. umber of,perforaHons is equal to one plus the number of 3.3 7 12 16 25 <br /> erforation spaces(4). Check figure E-4 to assure the number of 4.0 1 11 15 23 <br /> erforations�per lateral guarantees <10%discharge variation. 5.0 6 10 14 22 <br /> � a�d spaces+ 1 = a�perforations/lateral E-6: Perforatton Discharge in gpm <br /> 6. �A. Total number of perforaiions = perforations per lateral(5) perforation diometer <br /> Ihmes rnamber of laterals (1) head inches <br /> (feet) 3/16 7/32 1/4 <br /> �perfs/lat x ?� lat=�2,perforations <br /> 1 Aa 0.42 .5 OJ4 <br /> B. alculate 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 /> /D lEt x�_ft= �� 1 sqft a Use t.0 foot for single-family homes. <br /> ! Square foot per perforation=Rock bed area+number of perfs (6) b Use 2.0 feet fa on na, ei5e. <br /> ; 4�� ► sqft+ �7 perfs=�_sqft/perf Mq1�IFp�D �OCA7ED AT [Np pi pp[g$�tE pSTRIBl.710N MTEM <br /> � <br /> 7. �etermine required flow rate by multiplying the total number of <br /> �erforatior� (6A) by flow per perforation(see figure E-6) �13 a,`��,�a, � <br /> i <br /> ..�.� <br /> � 56 7 perfs x • �L gpm/perfs=�gpm <br /> 8. laterals are connected to header pipe as shown on upper ��,,,�; <br /> xample, ta select minimum required lateral diameter;enter M.,�`" ''�'�� <br /> 'gure E-4�rith perforation spacing(2) and number of perforations ��`"" � � <br /> er lateral �5) Select minimum diameter for <br /> urour a n�roiu•co nrc un�.0 ron <br /> erforated lateral= inches. Mcssw�e o�sr�rourror�M rwrw <br /> ,�{�[MM�RO RtlTK M[ <br /> 9. �f perforated lateral system is attached to manifold pipe neaz �`�,,,y,�,,,, g� �,„�� <br /> e center,lower diagram,perforated lateral length(3) and � �'�""`� M"'� <br /> r�0.e <br /> umber of perforations per lateral (5)will be approximately one R..�;,���b„�., <br /> �half of that in step 8. Using these values,select minunum '°• �- _ <br /> diameter for perfo t d 1 =��ir�e�ie,�° ;g�;.�, ��M a <br /> � •-��•�:s�.�: <br /> �; „� <br /> �f �� �.,•-,a::a•,w, ` �"� �rre"K,�•K <br /> �•;7 t.i'I`, iti ..�! /Mi�R• T <br /> 'iN; � ��M d <br /> I her by cerrify that I have completed this work in accordance with applicable ordinances, rules and laws. <br /> � �, � L� .. � <br /> (signature) 39 y (license#) I a- d -U O (date <br />