Full Product Manual

Table Of Contents
Page 68 Chapter 9
Determine Maximum
Lateral Lengths
The maximum length of a Landscape Dripline lateral is determined by the
maximum allowable pressure loss. The minimum inlet pressure should be 15 PSI.
As long as you meet this requirement, there is no need to calculate friction loss in
the Landscape Dripline lateral lines. Simply use Table 9-2 to determine the
maximum lateral lengths.
EXAMPLE
A change in elevation in the hydrozone will affect the maximum distance the
Landscape Dripline tubing can be run. Remember: 1 foot of elevation = .433
PSI. To determine exactly how much shorter (uphill) or longer (downhill) the
maximum lateral legnth can be due to a change in elevation, first calculate
the pressure loss (PSI) per foot of LD tubing on ground of zero slope.
Example: If the pressure at the start of your Landsape Dripline lateral is 45 PSI
and the flow rate is 0.9 GPH with emitters spaced at 12", the maximum
distance the tubing can be run without supplemental emitters is 236'. Since
the data assumes a minimum 8.5 PSI at the end of the lateral, the total pres-
sure loss for this distance is: 45 PSI - 8.5 PSI = 36.5 PSI.
Now divide this pressure loss by the maximum lateral length: 36.5 PSI/236' =
0.155 PSI loss per foot of LD tubing lateral. We will use this answer later to
determine how much shorter or longer the lateral can be due to slope consid-
erations.
Inlet Pressure Maximum Lateral Length (Feet)
PSI 12" Spacing 18" Spacing 24" spacing
15 159 130 222 174 283 214
25 252 171 359 231 457 287
35 304 211 435 289 558 358
45 342 236 489 322 627 399
60 392 268 558 365 716 453
Nominal
Flow (GPH)
0.6 0.9 0.6 0.9 0.6 0.9
Note: Data assumes a minimum 8.5 PSI at end of lateral.
Inlet Pressure Maximum Lateral Length (Meters)
BARS 30,5 cm 45,7 cm 61,0 cm
1,0 48,5 39,6 67,7 53,0 86,3 65,2
1,7 76,8 52,1 109,4 70,4 139,3 87,5
2,4 92,7 64,3 132,6 88,1 170,1 109,1
3,1 104,2 71,9 149,0 98,1 191,1 121,6
4,1 119,5 81,7 170,1 111,0 218,2 138,1
Nominal
Flow (l/h)
2,3 3,5 2,3 3,5 2,3 3,5
Note: Data assumes a minimum 0,6 bars at end of lateral.
TABLE 9-2: MAXIMUM LATERAL LENGTHS
Note: Data assumes a minimum 8.5 PSI at end of lateral for flushing purposes.
Note: Data assumes a minimum 8.5 PSI at end of lateral for flushing purposes.
®