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Irrigation systems Overview. Water pressure Hydraulics Site information Irrigation Water requirements Application Type Location Design Components Pre-season startup and winterizing an irrigation system. Basic hydraulics Static and dynamic pressure. Basic hydraulics
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Irrigation systemsOverview • Water pressure • Hydraulics • Site information • Irrigation • Water requirements • Application • Type • Location • Design • Components • Pre-season startup and winterizing an irrigation system
Basic hydraulicsStatic and dynamic pressure Basic hydraulics • Static pressure is the pressure in a “charged” line and is determined using a pressure gauge when water is not running through the system • Dynamic pressure is the measurement of pressure in a line as water flows through the line
Basic hydraulicsPressure and flow relationship • The larger the pipe the lower the pressure needed to deliver a given quantity (flow) of water • The smaller the pipe the greater the flow loss due to friction of the pipe and fittings
Basic hydraulicsSlope or gradient Pressure (head) • Increases by .433 psi/ft. of elevation change, or • Decreases by .433 psi/ft. of elevation change ☼ A rough figure of .5 psi per ft. of elevation change is typical
Site informationSand, loam, clay Determine soil type by using a • Soil probe • Hand test • Percolation test • Soil lab for analysis
Site informationHydrozones Planting groups with similar cultural and irrigation requirements Do NOT mix on the same valve: • Irrigation application methods • Sun and shade planting beds • North and south planting beds • Sloped and level areas • Drip irrigation with spray irrigation
Site informationValve by hydrozone • Design and place irrigation valves by hydrozone • Group plantings for proper microclimate and irrigation method
Site informationReflective heat or light Observe the area and keep a written record of • Heat or light damage • Wind exposure • Direction of prevailing wind
Irrigation water requirementLow-water use plants A well-designed and managed low-water use landscapeuses only5,000 – 10,000 gallons of water 1,000 sq. ft. annually
Irrigation water requirementsMedium-water use plants A well-designed and managed medium-water use landscape uses10,000 – 15,000 gallons of water 1,000 sq. ft. annually
Irrigation water requirementHigh-water use plants To maintain a “green” look in Sonoma and Marin counties 22,440 gallons of water 1,000 sq. ft. turf annually
Irrigation water requirementManufacturers’ catalogs • Use pipe flow charts to determine correct pressure and corresponding flow through a given size pipe • Use nozzle charts to determine correct sprinkler nozzle ☼ Do not mix nozzles types or brands when repairing an irrigation system
Irrigation application methodOverhead Rotor Spray Multi-stream rotating nozzle
Irrigation application methodOverhead Stream spray Micro-spray
Irrigation application methodPoint source Bubbler Drip
Irrigation application methodProper valve location Locate valves close to • Sidewalk • Areas to be irrigated ☼The turf area surrounding the valves is poorly designed and hard to maintain. ☼Do not hide valves under plants
Irrigation componentsWater meter A water meter measures the amount of water used ☼ A valuable conservation tool
Irrigation componentsBackflow device Ensures water quality by preventing the contamination of potable (drinking) water supply ☼ Check with local building officials for regulations about backflow prevention devices
Irrigation componentsBackflow device Reduced pressure double check valve (RP) • Must be inspected annually by a certified backflow inspector ☼ Check local regulations and codes for proper installation and maintenance
Irrigation componentsBackflow device Double check valve • Usually located in underground valve boxes ☼ Check local codes to see if this device is approved in your area Pressure vacuum breaker • Old technology ☼ Not approved for any new construction in this area
Irrigation components Backflow device Atmospheric breaker valve (ABV) • Also known as an anti-siphon valve • Often used in conjunction with a “master” valve • Subject to contamination by insects and debris ☼Must not be used on irrigation lines under constant pressure
Irrigation componentsPressure regulator A pressure regulator regulates water pressure to improve performance of the irrigation system ☼ See “How to adjust a prv (YouTube video)”
Irrigation components Solid state controllers Controllers with Liquid Crystal Display (LCD) • Interior mount and exterior mount available • Many have non-volatile memory • Have multiple programs to group irrigation valves by hydrozone • Terminal Strip for valve wires • Battery backup • Station Module
Irrigation componentsSensors for controllers Rain shut-off devices • Interrupts 24 volt electrical signal during periods of measurable precipitation (rain, dew)
Irrigation componentsSensors for Controllers Flow sensors • Monitors volume of water flowing through irrigation system piping • Interrupts 24 volt electrical signal when flow exceeds maximum flow desired • Used in conjunction with a “master valve”
Irrigation componentsSensors for controllers A freeze and/or wind sensor interrupts 24 volt electrical signal during freezing weather or high winds.
Irrigation componentsWiring Irrigation wiring • Wiring compartment – Line (110 volt) and Low (24 volt) are in separate areas of controller • Transformer – reduces line voltage (110v) to low voltage (24v) • Group signal and common wires leading to valves with mainline • Controller and valves are termination points for low voltage irrigation wiring
Irrigation componentsPVC piping Function • White PVC pipe is used for potable water • Purple pipe PVC pipe is used for non-potable water Schedule and Class • Sch. 40 & 80 PVC can be used for both mainlines and lateral lines • Class 200 PVC should only be used for lateral lines
Irrigation componentsManual valves Mainline isolation valves • Shut off portion of pressurized mainline
Irrigation componentsManual valves Manifoldisolation valves • Shuts off irrigation water to individual irrigation manifolds
Irrigation componentsValve group-manifold Manifold of atmospheric breaker (anti-siphon) irrigation valves
Irrigation componentsElectric remote control valves Electric remote control
Irrigation componentsDrip irrigation valve Drip irrigation valve • Install with drip filter and pressure regulator
Irrigation componentsIn-ground valve In-groundvalve • Electric remote control • Locate in valve box
Irrigation components – Above groundAnti-siphon valve Drawing and text courtesy of: Jess Stryker's Landscape Irrigation Installation Tutorialwww.IrrigationTutorial.com
Irrigation componentsSpray sprinklers Pop-up spray sprinklers Pop up rotors
Irrigation componentsImpact sprinklers Impact sprinkler heads
Irrigation components Bubbler Point source application • Bubbler on fixed riser
Irrigation componentsDrip emitters Point source application • Inline drip tubing installed on above ground
“As-built plans” Created during the job or any time after irrigation installation and reflects the system layout as it was actually installed • Design changes are recorded and highlighted to facilitate future repairs or modifications to system ☼ Maintenance contractors use these plans to record and map the irrigation system
Preseason inspection/maintenanceController check-up • Proper date and time • Adjust runtimes for a spring schedule • Replace battery back-up • Activate valves
Preseason inspection/maintenanceFlush irrigation system • Remove end cap or farthest sprinkler head • Activate valve for 30 seconds or until water is clear • Turn off valve and replace end cap / sprinkler head • Clean individual sprinkler screens
Preseason inspection/maintenanceSystem check-up • Activate the valve • Look, listen and feel - walk the station - adjust spray patterns - check for leaks, breaks and leaky valves • Flag troubled areas • Repeat with all valves • Fix flagged areas
Postseason inspection/maintenanceWinterize • Turn off water at main valve • Set auto controller to “rain” or “off” • Release pressure in pipes, then close • Drain water out of system and parts • Install freeze blanket on backflow device
Irrigation SystemsSummary Know how to determine static and dynamic water pressure Understand the effects of elevation change on an irrigation system Be familiar with water requirements of plants Understand the relationship between application devices, sensors and application rates Be familiar with irrigation system components and function Know how to perform pre-season checkups and how to winterize an irrigation system
Irrigation Systems Question & Answer What is wrong with this picture?