Side roll Wheel roll Sprinklers Layout Consideration Obstacles
Side roll / Wheel roll Sprinklers
Layout Consideration § Obstacles § Fences § Power lines § Out buildings § Ditches § Roads § Wind
Example Fence Power line Ditches Buildings Road
Irregular Field Shape
Slope § With the slope vs. Cross slope Laterals are generally laid out perpendicular to the slope
Set Times § Convenient set times § 23. 5 hrs § 11. 5 hrs § 7. 5 hrs * Allows ½ hour drain time 7. 5 hr not popular. One move allways in the dark
Lateral set sequencing § Irrigate every move across the field roll back to the front and start again § Skip irrigate every other move irrigate the skipped moves on the way back § Irrigate every move across the field second time use a offset pipe. Alternate back and forth
Uniformity Affected by § Base Pressure § Pressure variation § Overlap § Application Rate § Wind
Base pressure Match spacing to pressure Rule of thumb § 45 to 65 psi – 40 x 60 and 40 x 50 § 35 to 45 psi – 30 x 40 and 40 x 40 § 25 to 35 psi – 20 x 30 and 30 x 30 § Drains may not operate properly under 24 psi
Pressure Variation Affected by § Elevation difference § Up and down slope vs cross slope § Mitigate with flow control nozzles or pressure regulators § Friction loss § Pipe sizing § Limit pressure variation to 20% of design operating pressure
Overlap Rule of Thumb 50% along lateral 65% between laterals Example: 40 x 50 spacing Sprinkler diameter would need to 77’
Application Rate § Too small – wind problems § Too Large runoff § Match to soils and Irrigation interval
Wind Causes § Poor uniformity § Fine sprays § High pressures § High trajectory § Structural damage
Affects of wind
Wind Solution § § § Low trajectories Low pressure Course sprays Offsets Braces
Alternate sets
Example of multiple passes
Maintenance § § § Nozzles Gaskets Drains Levelers Springs/rotation
Big Guns or Traveler Sprinklers
Cart Style
Solid Set
Hose Reel
Layout § Hose drag § Solid set § Rectangular vs. triangular
Typical hose drag layout Traveler direction Travel lanes Buried or Portable main line Up to ¼ mile (1320’) Connection to main
Solid set
Solid set layout
Layout options Triangular layout Rectangular Layout
Layout for wind
Trajectory angle § § Optimization of pattern uniformity Minimize wind drift Maximize radius of throw Best drop condition
Application Rate § Match to soil § Runoff § Sealing
Pressure § 60 psi minimum Why § Throw distance § Stream breakup § Crop and soil damage
Riser Assembly § § Vertical Stable against vibration Low turbulence Protected from animals and machinery
Thrust § Causes § Tipping § Vibration § Fatigue and damage to joint § Solution § § Aluminum tripod Concrete block Post Swing elbow
Concrete support
Tripod Support
Swing Elbow detail
Stability § With a stable riser § Drive arm works properly and increases uniformity § Vibrations are dampened protecting pipe § Stream throw radius is maximized giving greater coverage
Safety § Big flow, lot of pressure can do damage to human, animal or infrastructure.
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