Irrigation Professionals with questions about ... - Hunter Industries

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Line #14 - Pressure Loss in the Isolation Valves: Isolationvalves may be gate valves, ball valves, or globe valves. While there willbe a meter cock or curb stop in most municipal systems, the pressurelosses incurred are generally considered minimal. If they are included,pressure losses can be estimated by use of the equivalent length chart,“Pressure Loss in Valves and Fittings,” on page 10 in the <strong>Hunter</strong> FrictionLoss Tables at the end of this design manual.There are no isolation valves in this example.Line #15 - Other Pressure Losses: These may include pressurelosses through backflow prevention devices, filters, or other systemcomponents located between the water source and the POC. There arenone in this example.Line #16 - Pressure Loss from the Source to POC: Add thepressure losses recorded on lines 12 - 15.Sample Problem: 7.0 + 2.72 + 0.0 + 0.0 = 9.72 PSILine #17 - Approximate Dynamic Pressure at DesignCapacity:1) Record the pressure previously determined on line #5.2) Record the pressure loss subtotal from line #16.3) Subtract these two lines to determine the approximate dynamicpressure expected at the POC at the maximum system flow rate(Design Capacity).Sample Problem:pressure from line #562.21 PSIpressure loss subtotal from line #16 - 9.72 PSIapproximate Dynamic Pressure at the POC 52.99 PSI
D. Estimate Pressure Available at"Worst Case" HeadAt this point the Design Capacity (GPM from line #11) and DynamicPressure at the POC have been calculated. The Design Capacityestablishes the maximum flow rate for the system and the DynamicPressure at the POC provides us <strong>with</strong> a basis for estimating the dynamicpressure that will be available to operate the sprinklers.In order to begin our irrigation system design an estimate of the availabledynamic pressure at the worst case head must be made. This is calculatedby:1) Adding or subtracting the pressure change due to the change inelevation between the POC and the highest head in the system.2) Estimating the amount of pressure that would remain after normalpressure losses between the POC and the highest head; typically 1/3 ofthe available dynamic pressure is lost and 2/3 remains available forsprinkler operationLine #18 - Pressure Change Due to Elevation Change:Calculate the pressure change due to elevation between the POC and thehighest head.Sample Problem: the highest head is 10 ft. above the POC.10 x 0.433 = 4.33 PSILine #19 - Estimated Pressure Available for SprinklerOperation: If the highest head in the system is above the POC, subtractthe pressure change calculated on line #18 from line #17, if the highesthead is lower than the POC, the pressure change from line #18 must beadded to the pressure on line #17.Sample Problem: 52.99 - 4.33 = 48.66 PSILine #20 - Two Thirds Estimate: A normal landscape irrigationsystem will lose approximately one third (1/3) of the dynamic pressureavailable between the POC and the highest head. These losses occurbecause of friction loss in pipe, pressure loss in valves and fittings, andpressure loss through check valves or other system components. Becauseof these losses, only two thirds of the dynamic pressure available at thePOC is available for sprinkler operation. In this step, multiply the pressuresubtotal calculated on line #19 by 2/3 (0.67).Sample Problem: 48.66 x 0.67 = 32.60 PSI
Page 1 and 2:
Irrigation Professionals with quest
Page 3 and 4:
Plot PlansIntroductionOne of the mo
Page 5 and 6:
Drawing ToolsThere are just a few t
Page 7 and 8:
Measure the PropertyTake careful me
Page 9 and 10:
Trees, water meters, and other item
Page 11 and 12:
Step 2 - Redraw On Graph PaperThe n
Page 13 and 14: SymbolsIn order to distinguish betw
Page 15 and 16: Make sure the drawing is dated and
Page 17 and 18: Step 4 - Group Sprinklers Into Zone
Page 19 and 20: Basic HydraulicsIntroductionHydraul
Page 21 and 22: How Pressure is Created By the Weig
Page 23 and 24: Does the Shape or Size of the Conta
Page 25 and 26: L O W24 VAC 50-60 Hz60mA INRUSH60mA
Page 27 and 28: Factors Affecting Dynamic PressureW
Page 29 and 30: INSIDE DIAMETER (i.d.) of the pipe:
Page 31 and 32: LENGTH is the fourth factor affecti
Page 33 and 34: D) SDR -Standard Dimension Ratio -
Page 35 and 36: 1. Look in the left column (FLOW G.
Page 37 and 38: SummaryThere is a limited amount of
Page 39 and 40: DefinitionsUse the diagram below al
Page 41 and 42: Calculating Dynamic Pressure at Des
Page 43 and 44: D. Estimate Pressure Available at
Page 45 and 46: Line #5 - Service Line: This is the
Page 47 and 48: Line #11 - Volume Through the Meter
Page 49 and 50: C. Calculate Dynamic Pressure at De
Page 51 and 52: Line #16 - Pressure Loss in the Wat
Page 53 and 54: Line #21 - Pressure Change Due to E
Page 55 and 56: Design ProblemMany times, you will
Page 57 and 58: III. Systems Supplied by a PumpCalc
Page 59 and 60: D. Estimate Pressure Available at
Page 61 and 62: Line #5 - Pressure at POC: If the P
Page 63: Sample Problem: 13.5 GPMC) Read acr
Page 67 and 68: (METERED SYSTEMS)Design Capacity an
Page 75 and 76: (PUMP SYSTEMS)Design Capacity and W
Page 77 and 78: (PUMP SYSTEMS)Design Capacity and W
Page 79 and 80: Sprinkler SelectionIntroductionThe
Page 81 and 82: Spray HeadsFixed spray heads may be
Page 83 and 84: Selecting the Proper SprinklerNow t
Page 85 and 86: Precipitation RateExpressed in inch
Page 87 and 88: Sprinkler Watering PatternsMost spr
Page 89 and 90: Choosing Nozzles for Gear Driven Ro
Page 91 and 92: 5) Sprinkler Watering Patterns - Be
Page 93 and 94: HydrozonesA hydrozone is a portion
Page 95 and 96: Triangular spacing is usually the p
Page 97 and 98: and flow rate, the smaller the spri
Page 99 and 100: perpendicular (see Figure 33). Many
Page 101 and 102: “symmetrical” layout, and they
Page 103 and 104: Head spacing in narrow areas is det
Page 105 and 106: Head placement is complicated becau
Page 107 and 108: Figure 40PGJ
Page 109 and 110: On larger slopes, a combination of
Page 111 and 112: SummarySprinkler head placement is
Page 113 and 114: Backflow PreventionIntroductionBack
Page 115 and 116:
System LayoutLaying out a system be
Page 117 and 118:
Backflow Preventer LocationLocal pl
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time. Station run time can be tempo
Page 121 and 122:
Pipe Sizing Using the Friction Loss
Page 123 and 124:
Backflow Preventer and Valve Sizing
Page 125 and 126:
Friction LossesIntroductionCalculat
Page 127 and 128:
5. Multiply your answer by the leng
Page 129 and 130:
Friction Loss CalculationsZone Numb
Page 131 and 132:
Sample Problem:1.67= 0.0167 psi los
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Step 2Step 3Step 4Step 5Step 6Sprin
Page 135 and 136:
Using the acceptable 10% allowance:
Page 137 and 138:
SummaryCalculating the friction los
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Page 141 and 142:
Page 143 and 144:
Precipitation RatesIntroductionToda
Page 145 and 146:
Sprinkler Precipitation RatesVersus
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Area CoveredArc by Sprinkler Flow90
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The Sprinkler Spacing MethodThis me
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Use of Precipitation Rates in Lands
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Irrigation SchedulingIntroductionUl
Page 155 and 156:
Crop coefficient. Different plants
Page 157 and 158:
ET Evaporation of soil surface wate
Page 159 and 160:
Soil Intake RateSoil texture will p
Page 161:
What You Need to KnowAs previously
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