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PRESSURE DISTRIBIITION SYSTEM Geotextile fabric
<br /> 1. Select number of perforated laterals 3 uarter inch erforatlons s aced re?3� 12 ��
<br /> 2. Select perforation spacing =�_ft g"of-rock
<br /> N
<br /> Perf Sizing 3/16"- 1/4" •
<br /> 3. Since perforations should not be placed closer than 1 foot to Perf Spacing 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 of 1/4-Inch perforations
<br /> per lateral to guarantee<10%discharge variation
<br /> �-�-�Y�-T� -2 ft = (�S� ft pertoration
<br /> spacing
<br /> 4. Deterui.ine the number of spaces between perforations. teet 1 inch 1.25 inch i.s inch 2.o inch
<br /> Divide the length (3)by perforation spacing (2)and zound
<br /> down to nearest whole number. 2,5 8 14 18 28
<br /> Perforation spacing= �r ca ft=�ft=3 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 4.0 7 11 15 23
<br /> perforation spaces(4). Check figure E-4 to assure the number of 5.0 6 10 14 22
<br /> perforations per lateral guarantees <10% discharge variation.
<br /> ��— spaces + 1 = �'�� perforations/lateral E-6: Periorotlon Discharge in gpm
<br /> 6. A. Total number of perforations = perforations per lateral (5) perforatfon diameter
<br /> times number of laterals (1) heod inches
<br /> (feet) 3/16 7/32 1/4
<br /> �_perfs/lat x�_.lat=�perforations �.Oo 0.42 0.56 0.74
<br /> B. Calculate the square footage per perforativn. 2,Ob 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 /> _��ft x (�$_ft= (0�60 sqft a use 1.0 foot for single-family homes.
<br /> Square foot per perforation =Rock bed area +number of perfs (6) b Use 2.0 feet for an hIn else.
<br /> � O� Sql l"} b / perfs = �. SS sqft/perf � ,.,,,,�� �OCATED 1T END OF PRESSURE OISTRIBUTION SYSTEM
<br /> 7. Deternune required flow rate by multiplying the total number of
<br /> perforations (6A) by flow per perforation(see figure E-6) „.,-�
<br /> �
<br /> �_p �gp 1/p p�'� gp .,.�o..
<br /> (o erfs x . (o m er s=�� m
<br /> 8. If laterals are connected to header pipe as shown on upper � '�
<br /> `�� ari��nca.
<br /> example,to select minimum required lateral diameter;enter ,,,��►d"`" .�'.'"
<br /> figure E-4 with perforation spacing (2) and number of perforations ��`"`M
<br /> per lateral (5) Select rs�nimum diameter for
<br /> 41'OUT OI►C�fpUT[0�I�[I�TC��lS IDR
<br /> MCSSU11f D�STR�pui10N W HOUNO
<br /> perforated lateral = inches.
<br /> �{-Kll�OiuT[D RAfTK Ir(
<br /> 9. If perforated lateral system is attached to manifold pipe near `�,�,,,,,,,,,,R,,,a,„• „�,y��
<br /> the center,lower diagram,perforated lateral length(3) and �w �`�'""`�"`�"r'� -"""��
<br /> r��ao
<br /> number of perforations per lateral (5)will be approximately one K,.�;��,,�;�b..a�
<br /> half of that in step 8. Using these values, select miniinum '° '_ _ �,
<br /> o}�nrt".�°�'rv':.°:�
<br /> diameter for perforated lateral = �1 �Z inches.
<br /> _�.��.. a ,�R,�
<br /> - ,�
<br /> � Aa'�rr� :,,,;,,.�n �
<br /> �K �
<br /> ��i�TM
<br /> I hereby certity that I have completed this work in accordance with applicable ordinances, rules and laws.
<br /> ( �/� L"� - �`�----- (signature) :>`7�-I (license#) 7—)—C�Z (date)
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