Laserfiche WebLink
PRESSURE DISTRIBUTION SYSTEM Geotextile fabric <br /> 1. Select number of perforated laterals � uarter inch erforations s aced @ 3� 12�� <br /> 2. Select perforaHon spacing = �.o ft 9"of.ro�k <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 allowoble number of 1/4-inch perforations <br /> �� per lateral to guarantee<10%discharge variation <br /> Rock layer length � � f t - �� ft <br /> perforation <br /> 4. Determine the number of spaces between perforations. spacing <br /> Divide the length (3) by perforation spacing (2) and round feet 1 inch 1.25 inch 1.5 inch 2.0 inch <br /> down to nearest whole number. <br /> 2.5 8 14 18 28 <br /> Perforation spacing = (Pto ft= 3.�J ft=��spaces 3.0 8 13 17 �26�, <br /> .-- _. __ <br /> 5. Number of perforations is equal to one plus the number of <br /> 3.3 7 12 16 ._t. .._._ 25 <br /> perforation spaces(4). Check figure E-4 to assure the number of 4�0 > >> 15 23 <br /> perforations per lateral guarantees <10% discharge variation. 5.0 6 10 1q 22 <br /> �a, _sPaces + 1 = a'� perfarations/lateral E-6: Perforation Dischorg� 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 0.56 �.74 <br /> B. Calculate the square footage per perforation. <br /> Should be 6-10 sqft/perf. Does not apply to at-grades. 2•0b 0.59 0.80 1.04 <br /> Rock bed area = rock width (ft) x rock length (ft) 5.0 0.94 1.26 1.65 <br /> �ft X �a�f ft = �t,v Sgft ° 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 Thin else. <br /> ��c� sqft=�perfs = .�, sqft/perf <br /> MnNIFOLD LOCATEO GT ENO OF pqE55URE DISTflIOUTION 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 /> ��3�`��A�'� ��� <br /> ��perfs x 1 S►�gprn/perfs =�_gpm �- <br /> 8. If laterals are connected to header pipe as shown on upper %�::�" <br /> example, to select ininiii�um required lateral diameter;enter ,�,�N«°`"`� ,�":w`" .` <br /> figure E-4 with perforation spacing (2) and number of perforations ��``""�d <br /> per lateral (5) Select minimum diameter for <br /> perforated lateral = a indles, u���� ��PER(OMiEO P,PE LaiEPaLS{pq <br /> PRESSURE OISTPIBul1�N W MO�NO <br /> R.�SI�[�iP( <br /> 9. If perforated lateral system is attached to manifold pipe near �,�„o�,,,a,� .�,x. y,�,� <br /> the center, lower diagram,perforated lateral length (3) and °Ew a'�`-`""`"`�"�^"�' - ^"'�°""�� <br /> r���„ ��� <br /> numUer of perforations per lateral (5) will be approximately one K �, „�,, <br /> half of that in step 8. Using these values, select minimum �'�T,�S,���.� � <br /> [F� 1 <br /> diameter for perforated lateral = "-�--_-� inches. �'"'"`'�°^ <br /> �o�., � �„[w•' ��., fl <br /> �.r�o <br /> \ ��M�M d/` <br /> \`r <br /> I hereby certify that I have c�mpleted this work in accordance with applicable ordinances, rules and laws. <br /> ,��-- �� �'r� �_...�.,, <br /> (signaiure) _ 3�7�} (]icense#) I a -l�-04� (date) <br />