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Dura-Flo PC

Slopes

-Introduction

-Basic Layout

-Additional Layout Options

-Soil-Water Relationship

-Product Selection Guide

-Spacing Between Dripperlines

-Length of Dripperlines

-Other Components

-Slopes

-Simplified Design

-Subsurface Systems

-System Monitoring

-Application Rates

-System Flow Rates

-How to Specify

-Technical Data

-Performance Specs

 		 Slopes need to be treated a little differently from flat areas because of the way the water moves through the soil and also because water in the DURA-FLOTM PC dripperline, supply and exhaust headers and piping could drain through the lowest emitter of the DURA-FLOTM PC dripperline when the system is shut off.

To minimize these problems the following is suggested:

1. Run the DURA-FLOTM PC dripperline across, not down, the slope.

2. Use smaller zones, (separate grids), when there are slopes. As a general rule of thumb, design the zones to limit the elevation change to 10' (± 4 psi).

3. In steep slopes, the use of inline check valves should be considered.

4. When the DURA-FLOTM PC dripperline is running across the slope and the elevation drop from the top dripperline to the bottom dripperline in the same zone exceeds 3 feet, it is recommended to increase the spacing between dripperlines progressively as they move down the slope. See Chart 3.

 

Chart 3

Dripperline Spacings on Slopes
Total Elevation Change Aggregate Increase in Dripperline Spacing
3' 5%
5' 10%
7' 15%
10/ 25%

To use this chart, calculate the total elevation change from the top dripperline to the bottom dripperline within the zone and then look up the appropriate recommended total increase in dripperline spacing. Remember this number represents the total change from the first spacing to the last spacing. The spacing increases progressively from top to bottom.

The following example explains this calculation.

Example:

Elevation change is 10' downhill, recommended DURA-FLO PC dripperline nominal spacing for flat ground is 20", with 11 rows of dripperline.
 

Qustion:

What is the actual spacing between dripperline to allow for the slope?
   

Solution:

From Chart 3, page 11, spacing should be progressively increased by a total of 25%. (Final spacing is 25% more than initial spacing).

Between Dripperline
Number		 Spacing
Increase		 Recommended
Spacing
1 and 2 2.5% 20.5"
2 and 3 5.0% 21.0"
3 and 4 7.5% 21.5"
4 and 5 10.0% 22.0"
5 and 6 12.5% 22.5"
6 and 7 15.0% 23.0"
7 and 8 17.5% 23.5"
8 and 9 20.0% 24.0"
9 and 10 22.5% 24.5"
10 and 11 25.0% 30.0"

Note: Dripperline 1 is at the top of the slope, dripperline 11 is at the bottom of the slope.