Micro Irrigation Calculator
for
- Tree & Vine Daily Requirement / Precipitation Rate
- PC Dripline, Rain Bug PC, and Lady Bug Lateral Friction Loss
- Micro Quick Lateral and Feeder Tube Pressure Loss
- Manifold Pressure Loss and Diameter
Formulas
and Conversions (PDF: 73 KB)
Instructions:
1. Click on the window and the drop down list of calculations
appear.
2. Choose which solution is desired.
3. Enter values for each prompted input. For lateral or manifold calculations,
enter the emitter or lateral outlet flows. Calculations include emitter
or barb obstruction pressure loss.
NOTE: For repeat calculations, choose Reset first.
4. The answer displays in the right window when finished. Additional
calculations will display in the window below.
5. Use reference charts for PVC pipe inside diameter.
6. Use the "Sprinkler Irrigation Calculator" for mainline, pump brake
horsepower,
and waterhammer calculations.
Example:
A micro spray system for oranges is considered where the tree
spacing is 16 feet and the row spacing is 16 feet. The crop peak evapotranspiration
(ET) is .3 in/day and the application efficiency is 85% (.85). A Micro
Quick 12 gph blue nozzle is chosen for a lateral with I.D. of .830 in.
and length of 400 feet. The pressure on the last micro spray on the
lateral is 15 psi. There are 20 laterals on the manifold. Desired pressure
loss in the manifold is not to exceed 2 psi.
1. The Tree daily requirement = 56.3 gal
Also, Lateral tubing per acre = 2272 ft.
2. The Precipitation rate = .075 in/hr, gpm / ac = 34
3. The Micro Quick lateral pressure loss = 2.6 psi,
Also, Total flow = 4.19 gpm, flow variation = 8.4 %
4. The Micro Quick feeder tube pressure loss = 0.8 psi
5. The Manifold required size = 2.54 in.
Also, Total flow = 83.0 gpm, max. velocity = 5.3 fps
6. Choose 2 1/2" IPS 125 pipe.
Manifold pressure loss = 1.5 psi
