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� � � PRESSURE DISTRIBUTION SYSTEM Geotextile fabric
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<br /> 1. Select number of perforated laterals = a=��s�h,'erforaHons accd�3' . _
<br /> : r . ..A. �p t � - .
<br /> . . . � �e � r .,;�:�.J r: i'�`t,��� ' .
<br /> 2. Select perforation spacing= 3, a ft , � :',�� .r:`'�.'
<br /> Perf 3/16"-1/4"
<br /> 3. Since perforations should not be placed closer than 1 foot to p���'g l.s�-5�
<br /> the edge of the rock layer(see diagram)�subtract 2 feet from
<br /> t�e rock layer length. E-4: Maximum aQowcble rxmiber of 1/4inch pedoraHons
<br /> per laterai b�uar�tM<t0%d�chor�e vadotion
<br /> .�� -2 ft = a � ft pertoraaon
<br /> . :P� �
<br /> 4. Determine the number of spaces between perforations. }ee l��ch 1.25 inch .1.b•Inch 2.o inch
<br /> Divide the length(3)by perforation spacing(2)and r�iu�
<br /> ��to nearest whole nwnber. 2;5 8 �14 18 28
<br /> Perforation spacing= a`� ft+�ft=�spaces 3•U � 8 13 » 26
<br /> 3.3 1 12 16 � 25
<br /> 5. Number of perforations is equal to one plus the number of 4 0 � �� �5 23
<br /> perforation spaces(4)..Check figure E-4 to assure the number of �.p 6 l0 t4 22�
<br /> perforations per lateral guarantees<IO%discharge variation.
<br /> . /c�spaces+1 = // . p�rfOrations/lateral E-6: Porforation Dischcrpe In gpm
<br /> 6. A: Total number of perfora#ions= perforations per l�teral (5) perforation dlometer
<br /> times number of laterals(1) head inches
<br /> (feet) 3/16 7/32 1/4
<br /> �„�_perfs/lat x_�_lat=�_perforations �,pa 0.42 0.56 0.74
<br /> B. Calculate the square footage per perforation. 2,pb 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 /> a �- I(� ft X 3 1 �t c�a� 3C1� ° Uae 1.Q foot Mr ainpte-tamily homes.
<br /> Square�foot per perforation=Rock bed area+number of perfs (6) b u�z.o re.r ror ar, i� eise.
<br /> �:z sqft+�Perfs= g,� �sqft/perf ,�, ,:�,.T �a.� ��e�� �M
<br /> 7. Determuie required flow rate by multiplying the t�otal number of
<br /> perforations (6A) .by flow per perforation'(see figure E=6) "�"
<br /> �j� �,�, ��
<br /> �perfs x � '� n1/perfs= 4� _SPm . ,
<br /> 8. If laterals are connected to header.pipe as shown on upper �b�� r
<br /> � �,;�.�,.
<br /> example,to select miniinum required lateraFdiameter;enter �,,,.�
<br /> figure E-4 with perforation spacing(2)and number of perforations ��
<br /> per lateral(5) Select�minimunt diameter for ,,,�,,,a.�,,,..,.,��n,,.�,,�,
<br /> nKswwt a�rm�unon w►auMo
<br /> perforated lateral= l�inches.
<br /> �IO�M�Mp AMtK NK
<br /> 9. If perforated lateral system is attached to manifold pipe near ,� �`""
<br /> �� M�
<br /> the center,lower diagram,perforated lateral length.�3)and r.y,�..
<br /> number of perforations per lateral(5)will be approxiYriately one :•��,�»��«-
<br /> half of thafi in step 8. Using these values,select minimum , ` - -,�•�r�„+.�
<br /> diameter forperforated lateral= inches. a�. �, �
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<br /> I hereby certify that I have completed this work in accordance with applicable ordinances, rules and laws.
<br /> � �,� ' i ature) �`� (license#) � �i a'��(date)
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