Page 330 - Toro Irrigation Product Catalogue August 2020

Drip Equations

Number of emitters per plant Thermal effects on dripline
For recurring, ambient temperatures above 23°C, multiply pressure
canopy area (square meters) x 0.75
Emitters per plant = rating of selected tubing by the appropriate FACTOR from the table
wetted area per emitter (square meters)
below. Result will be the temp-corrected maximum pressure rating
for the tubing selected. For temperatures not shown but between
Wetted Area per Emitter 23°C and 60°C, interpolate to obtain the temp-corrected maximum
Soil Type Diameter (meters) Area (meters ) 2 pressure. Use this information to select the appropriate pressure
Sand 0.6-0.9 0.3-0.7 regulator to assure tubing life expectancy and warranty coverage.
Sandy Loam 0.9-1.4 0.7-1.5
Loam 0.9-1.5 0.7-1.9
Clay-Loam 1.2-1.8 1.2-2.6
Clay 1.5-2.1 1.9-3.5 °C Factor
23 1.00
Flow per zone
27 0.92
total number of drippers x dripper flow rate (lph)
Flow per zone (lpm) =
60 (minutes) 32 0.81
38 0.70
Precipitation Rate for Evenly Spaced Single Laterals
and Emitters 43 0.60
49 0.45
Precipitation Rate for Evenly Space Drip Line (mm/hr)
54 0.32
Emitter Emitter Spacing between Drip Lines (cm)
Flow Spacing 60 0.18
(Lph) (cm) 30 40 50 75 100
1.2 30 13.3 10.0 8.0 5.3 4.0
1.2 50 8.0 6.0 4.8 3.2 2.4
1.2 75 5.3 4.0 3.2 2.1 1.6
1.5 30 16.7 12.5 10.0 6.7 5.0
1.5 50 10.0 7.5 6.0 4.0 3.0
1.5 75 6.7 5.0 4.0 2.7 2.0
2.4 30 26.7 20.0 16.0 10.7 8.0
2.4 50 16.0 12.0 9.6 6.4 4.8
2.4 75 10.7 8.0 6.4 4.3 3.2

Precipitation Rate Formula
10 000 x Emitter Flow (lph)
Precipitation Rate (mm/hr) =
Lateral Spacing (cm) x Emitter Spacing (cm)
Note: this formula applies to evenlty spaced drip irrigation and emitters
Precipitation Rate for a Single Lateral

Precipitation Rate for a Single Drip Line in a contained
Landscape (mm/hr)
Emitter Emitter Width of Contained Landscape (m)
Flow Spacing
(Lph) (cm) 50 75 100 125 150
1.2 30 8.0 5.3 4.0 3.2 2.7
1.2 50 4.8 3.2 2.4 1.9 1.6
1.2 75 3.2 2.1 1.6 1.3 1.1
1.5 30 10.0 6.7 5.0 4.0 3.3
1.5 50 6.0 4.0 3.0 2.4 2.0
1.5 75 4.0 2.7 2.0 1.6 1.3
2.4 30 16.0 10.7 8.0 6.4 5.3
2.4 50 9.6 6.4 4.8 3.8 3.2
2.4 75 6.4 4.3 3.2 2.6 2.1

Precipitation Rate Formula
10,000 x Emitter Flow (lph)
Precipitation Rate (mm/hr) =
Width of Contained Landscape (cm) x Emitter Spacing (cm)

Company policy is one of constant improvement and therefore changes in specifications may
308 be made without notice and without incurring liability. Please refer to www.toro.com.au
Toro Australia Pty Ltd, 53 Howards Road, Beverley, South Australia, 5009.
Phone 1300 130 898, fax (08) 8243 2488. A.B.N. 47 001 310 443