Rain Bird Landscape Irrigation Design Manual

Landscape Irrigation Design Manual

cContentsForward .vIntroduction .viiStep one: Understanding basic hydraulics .3Static water pressure .4Dynamic water pressure .6Exercises on basic hydraulics .9Step two: Obtaining site information .13Step three: Determining irrigation requirements .19Soil type .19Exercises on site information and irrigation requirements .23Step four: Determining water and power supply .27Calculating water meter capacity and working pressure .27Rule number one .27Rule number two .28Rule number three .28Exercises on water capacity and pressure .30Step five: Selecting sprinklers and spacing ranges .35Selecting sprinklers .35Spray sprinklers .35Rotating sprinklers .35Bubblers and drip irrigation devices .35Exercises on selecting sprinklers .40Spacing sprinklers and calculating precipitation rates .41Exercises on spacing sprinklers and calculating precipitation rates .47Locating sprinklers on the plan .48Exercises on locating sprinklers .52Step six: Lateral layout, circuiting sprinklers into valve groups .55Locating valves, main lines and lateral piping .57Calculating lateral operating time .58Sample lateral number 1 .59Sample lateral number 2 .59Step seven: Sizing pipe and valves and calculating system pressure requirements .65Exercises on calculating system pressure requirements .71Step eight: Locating the controller and sizing the valve and power wires .75Locating the controller .75Sizing valve wires .75Sizing power wires .78Step nine: Preparing the final irrigation plan .83Exercises on system electrics and preparing the final irrigation plan .85Irrigation references .86Landscape Irrigation Design Manual iii

ContentsSolutions .89Solutions to exercises on basic hydraulics .89Solutions to exercises on site information and irrigation requirements .89Solutions to exercises on water capacity and pressure .89Solutions to exercises on selecting sprinklers .90Solutions to exercises on spacing sprinklers and calculating precipitation rates .90Solutions to exercises on locating sprinklers .90Solutions to exercises on circuit configuration and operating time .91Solutions to exercises on calculating system pressure requirements .91Solutions to exercises on system electrics and preparing the final irrigation plan .91Technical Data .94U.S. Standard Units .94Friction loss characteristics PVC schedule 80 IPS plastic pipe .94Friction loss characteristics PVC schedule 40 IPS plastic pipe .95Friction loss characteristics PVC class 315 IPS plastic pipe.96Friction loss characteristics PVC class 200 IPS plastic pipe.97Friction loss characteristics PVC class 160 IPS plastic pipe.98Friction loss characteristics PVC class 125 IPS plastic pipe.99Friction loss characteristics polyethylene (PE) SDR-pressure-rated tube .100Friction loss characteristics schedule 40 standard steel pipe.101Friction loss characteristics type K copper water tube .102Pressure loss in valves and fittings .103Pressure loss through copper and bronze fittings .103Climate PET .103Estimated service line sizes .103Pressure loss through swing check valves .104Soil characteristics .104Maximum precipitation rates .105Friction loss characteristics of bronze gate valves .105Slope reference .105Pressure loss through water meters AWWA standard pressure loss .106International System Units.107Friction loss characteristics PVC schedule 80 IPS plastic pipe .107Friction loss characteristics PVC schedule 40 IPS plastic pipe .108Friction loss characteristics PVC class 315 IPS plastic pipe .109Friction loss characteristics PVC class 200 IPS plastic pipe .110Friction loss characteristics PVC class 160 IPS plastic pipe .111Friction loss characteristics PVC class 125 IPS plastic pipe .112Friction loss characteristics polyethylene (PE) SDR-pressure-rated tube .113Friction loss characteristics schedule 40 standard steel pipe.114Friction loss characteristics type K copper water tube .115Pressure loss in valves and fittings .116Climate PET .116Estimated service line sizes .116Pressure loss through copper and bronze fittings .116Pressure loss through swing check valves .117Soil characteristics .117Maximum precipitation rates .118Friction loss characteristics of bronze gate valves .118Slope reference .118Pressure loss through water meters AWWA standard pressure loss .119Appendix.121Table of formulas .123Table of figures .124Index .129iv Landscape Irrigation Design Manual

ForwardThis manual was prepared at the request of numerousindividuals who either wished to learn the basic techniquesof landscape irrigation design or who are teachers of thesubject. Intended as a very basic text for irrigation design,this manual proceeds as if the reader has no priorknowledge in the subject.As you use this manual, be sure to review the practicalexercises at the end of each section. In some cases, newinformation and tips, not covered in the previous section,are found in the exercises.The main omission from a design manual such as this isthe real, hands-on experience of designing and theninstalling a landscape irrigation system. The editors of theLandscape Irrigation Design Manual hope such anopportunity is available to you and that the informationpresented here is of benefit.Landscape Irrigation Design Manual v

IntroductionProperly designed, installed, maintained and managedlandscape irrigation systems greatly reduce the volume ofirrigation water that is wasted every year. In some watershort areas, we have seen the beginnings of planned waterconservation efforts. In time, these could become the basisfor a coordinated national policy toward waterconservation. Today many municipalities require home orbusiness owners to submit irrigation designs for approvalprior to construction.This manual is part of the effort to promote properlydesigned landscape irrigation systems. It is our goal topresent the material as simply as possible while explainingsome theory behind the process. Understanding the basichydraulics material in the first section of the manual is veryimportant, especially to new students of irrigation design.Even intermediate level design students may find it helpfulto “brush up” on hydraulics before going on to furtherstudies. With that said, please turn the page to discoversome facts about the nature of water.Note: Information contained in this manual is based upongenerally accepted formulas, computations and tradepractices. If any problems, difficulties, or injuries shouldarise from or in connection with the use or application ofthis information, or if there is any error herein,typographical or otherwise, Rain Bird Sprinkler Mfg. Corp.,and its subsidiaries and affiliates, or any agent or employeethereof, shall not be responsible or liable.Note: Metric data (International System Units) containedin this manual is not always a one-to-one conversion fromU.S. measurements (U.S. Standard Units). Some metricdata has been altered to simplify examples. 2000 Rain Bird Sprinkler Manufacturing Corporation.All rights reserved.Landscape Irrigation Design Manual vii

UnderstandingBasic Hydraulics1

1Step one: Understanding basichydraulicsHydraulics is defined as the study of fluid behavior, at restand in motion. Properly designed piping, with soundhydraulics, can greatly reduce maintenance problems overthe life of an irrigation system. Controlling the water flowvelocity, holding velocity within proper limits, reduces wearon the system components and lengthens service life. Poorhydraulic design results in poor performance of theirrigation system, leading to stressed landscaping material,or even broken pipes and flood damage. Lack of designknow-how can also cost the system owner more moneybecause the designer may over-design the system to avoidunknown factors. In addition to wasting money, a poorhydraulic design will often waste water. Hydraulic analysisis important to minimize financial risks, produce efficientdesigns and eliminate waste.To accomplish all these things we need to understand thenature of water. Water takes the shape of the container.Water is relatively incompressible. Water is also quite heavy— one gallon (one liter) of water weighs 8.3 lbs (1 kg) andwater has a specific wei

Landscape Irrigation Design Manual v Forward This manual was prepared at the request of numerous individuals who either wished to learn the basic techniques of landscape irrigation design or who are teachers of the subject. Intended as a very basic text for irrigation design, this manual proceeds as if the reader has no prior knowledge in the .