Certified Irrigation Technician Program

Transcription

1 Certified Irrigation Technician Program An initiative of:

2 TABLE OF CONTENTS CHAPTER 1: Terminology Page 3 Soil Types Page 5 CHAPTER 2: Soil-water-plant relationships Page 6 CHAPTER 3: Hydraulics Page 10 CHAPTER 4: Design Page 17 CHAPTER 5: Installation Page 24 CHAPTER 6: Scheduling Page 27 CHAPTER 7: Service Troubleshooting Page 31 CHAPTER 8: Charts, Wire Sizing Page 36 An initiative of LANDSCAPE ONTARIO 2

3 CHAPTER 1: TERMINOLOGY Amp amperage is the current or flow of electrons (6,000,000,000,000,000,000 shifting at the speed of light). Backflow Prevention Device the device required by law, on an irrigation system that prevents water from reentering the potable water lines once it flows into the irrigation pipes. Controller the device that sends timing commands to remote control valves for actuation. Coverage the pattern of water applied to an area by a sprinkler head. Design Operating Pressure the pressure a designer uses to determine spacing distances and flow for sprinkler heads. The design operating pressure is determined by subtracting estimated friction losses from the static water pressure. Diaphragm the seal that divides the control chamber from the main body of a valve. Dynamic Pressure the pressure reading in a pipeline system with water flowing. Flow the movement of water through the irrigation piping system; causes friction loss. FPS the abbreviation for feet per second ; refers to the velocity of water in pipes. Friction Loss the loss of pressure (force) as water flows through the piping system. Ground a safe path of least resistance for electrons to shift to earth in the even of a shorted circuit. GPM the abbreviation for gallons per minute (unit of measure for water flow). Head-to-Head Spacing refers to the spacing distances of sprinklers when they do not exceed the radius of the sprinklers. Lateral the pipe in an irrigation system located downstream from the remote control valve. Lateral pipes carry water directly to sprinklers. Main Line the pipe in an irrigation system that delivers water from the backflow prevention device to the remote control valves. This is usually the largest pipe on the irrigation system, generally under constant pressure and located upstream from the remote control valves. Manifold a group of control valves located together in the same area. PSI the abbreviation for pounds per square inch (unit of measure for water pressure). PVC Pipe Poly Vinyl Chloride pipe; the most common pipe used in large irrigation systems, such as sports fields and golf courses. P.O.C. abbreviation for point of connection. This is the location on the irrigation system where a tap is made for connection of a backflow prevention device or water meter. Poly Polyethylene pipe; flexible black plastic pipe, commonly used on residential projects. An initiative of LANDSCAPE ONTARIO 3

4 Potable Water water used for drinking purposes. Precipitation Rate (PR) the rate at which sprinkler heads apply water to a specific area of coverage, over a given period of time, measured in inches per hour. Remote Control Valve the component in the irrigation system that regulates the on/off of water from the main line to the sprinkler heads; activated by the controller. Resistance the loss of voltage over a wire. Similar in hydraulic terms to friction loss. Service Line the pipe supplying water from the city water main to the water meter. Solenoid electro-magnet which when energized, lifts a plunger to open an outlet port to permit flow from a valve control chamber. Spacing the distance between the sprinkler heads or the sprinkler head rows. Static Water Pressure the pressure that exists in a piping system when there is no flow; measured in pounds per square inch (PSI). Station a group of sprinkler heads controlled by the same remote control valve. Surge the build-up of water pressure in a piping system due to certain characteristics of the pipe, valves and flow. Velocity the speed at which water flows through the piping system; measured in feet per second (FPS). Volt voltage is the electromotive force that compels electrons to shift. It can be chemical or magnetic in origin. Water Main the city water pipe located in the street or right-of-way. Water Pressure the force of water that exists in a piping system; measured in pounds per square inch (PSI). Working Pressure the remaining pressure in the irrigation system when all of the friction losses are subtracted from the static pressure. Zone A distinct group of like plant material, or site designated subgroup (i.e. baseball diamonds, soccer fields, etc.). An initiative of LANDSCAPE ONTARIO 4

5 IDENTIFICATION OF SOIL TYPES The United States Department of Agriculture defines soil separates as having the following diameters in millimetres: very coarse sand 2 to 1; coarse sand 1 to 0.50; medium sand 0.50 to 0.25; fine sand 0.25 to 0.10; very fine sand 0.10 to.05; silt.05 to.002; and clay below.002 mm. Sand: Sand is loose and single grained. The individual grains can be seen or felt. Squeezed in the hand when dry, it will fall apart when pressure is released. Squeezed when moist, it will form a cast, but will crumble. Sandy Loam: A sandy loam is a soil containing mostly sand but which has enough silt and clay to make it somewhat coherent. Squeezed when dry, it will form a cast that will fall apart. Squeezed when moist, a cast can be formed that will bear careful handling without crumbling. Loam: Silt Loam: Clay Loam: Clay: A loam is a soil having a mixture of different grades of sand, silt and clay in such proportion that the characteristics of none predominates. Squeezed when dry, it will form a cast that will bear careful handling, while the cast formed by squeezing the moist soil can be handled quite freely without crumbling. A silt loam is a soil having a moderate amount of the fine grades of sand and only a small amount of clay over half of the particles being of the size called silt. When dry, it may appear quite cloddy, but the lumps can be readily broken; and when pulverized, it feels smooth, soft and floury. When wet, the soil readily runs together. Either dry or moist, it will form cast that can be freely handled without breaking. A clay loam is a fine-textured soil that usually breaks into clods or lumps that are hard when dry. When the moist soil is pinched between the thumb and finger, it will form a thin ribbon, which will break barely sustaining its own weight. The moist soil is plastic and will form a cast that will bear much handling. When kneaded in the hand, it does not crumble easily. Clay is a fine-textured soil that usually forms very hard lumps or clods when dry and is quite plastic and usually sticky when wet. When the moist soil is pinched out between the thumb and finger, it will form a long, flexible ribbon. An initiative of LANDSCAPE ONTARIO 5

6 CHAPTER 2: SOIL-WATER-PLANT RELATIONSHIPS 1. SOILS A. Four components of soil: 1. Mineral matter Ideal 45% 2. Organic matter Ideal 5% 3. Water Ideal 25% 4. Air Ideal 25% B. Soil factors influencing plant growth: 1. Support anchor plant 2. Essential nutrient elements 3. Water needs 4. Oxygen requirements 5. Freedom from inhibitory factors (salinity) C. Physical properties of soils: Soil texture size of soil particles, relative proportions of the different size groups or separates. Soil structure arrangement of the particle (sand, silt, clay). Influences rate of water and air movement. Adding soil separates such as sand to clay soil can change texture; structure can be changed by tillage. Pore space contain air and moisture, size of pore space important. Soil colour. Soil temperature soil high in water content warms and cools slowly. NAME DIAMETER - MILLIMETERS Very coarse sand Course sand Medium sand Fine sand Very fine sand Silt Clay Below D. Soil Moisture: 1. Gravitational free, excess or drainage water. 2. Field capacity root zone filled to capacity. 3. Wilting point the point at which a plant will not revive, as quantity of moisture in soil becomes less the force by which it is retained increases. An initiative of LANDSCAPE ONTARIO 6

7 Water in relation to plant growth moisture enters the plant roots by osmosis; nutrients move with soil moisture. Transpiration evaporation of moisture from plant surfaces. Evapotranspiration evaporation of moisture from soil surface plus transpiration from leaf. Factors affecting soil moisture: 1. Sunlight 2. Temperature 3. Atmospheric vapour pressure 4. Wind 5. Soil moisture supply Liquid losses of soil water: 1. Percolation and leaching 2. Leaching losses of nutrients 3. Runoff E. Intake rate of soils: The soil s ability to take in water during the water application period. This rate is governed by the conditions of the soil surface and the physical characteristics of the soil. In general, a soil will take water at a relatively high rate for the first few minutes to the first hour or so. After an initial period, the intake rate will diminish until, after a period of time, depending on the soil, the rate will become more or less constant. CHART 1 Factors affecting intake rate: 1. Slope 2. Cover thatch reduces intake rate 3. Soil conditions texture, compaction 4. Water quality 5. Time 6. Water stored in soil before irrigation An initiative of LANDSCAPE ONTARIO 7

8 Factors that can improve intake rate: 1. Remove thatch or add cover 2. Aerate 3. Soil amendments 4. Short cycles F. Water-holding capacity The quantity of water that soils can hold in a form available for plant use is influenced mainly by the quantity of clay and organic matter in the soil and the physical properties of the clay. TABLE 2 - WATER HOLDING CAPACITY NAME IN/FT mm/cm Coarse sands Fine sands Loamy sands Fine sandy loam Silt loam Silty clay-loam Clay Heavy loam clay G. Salted or saline soils 2. PLANTS Soils containing sufficient soluble salts to impair their productivity are considered saline, and often called salted soils. Roots: Problem soils: 1. Saline white crust on the surface 2. Saline alkali 3. Nonsaline alkali slick spots darkened appearance Leaching improves saline conditions. Alkali soils are improved by soil conditioning. An alkali soil contains sufficient sodium to affect the soil chemically and physically. The primary method of water absorption by plants is by the roots. Water is first absorbed by the surface roots and then at successively deeper depths as the water supply is depleted. We can look at the soil as a reservoir for water. The amount of water the reservoir contains depends on the soil depth, and amount available to plants depends upon the depth of the roots. A small amount of water can be taken in through the leaves and stems. During periods of water stress, this may be enough to prevent serious desiccation. An initiative of LANDSCAPE ONTARIO 8

9 A. Factors that affect water absorption by roots: 1. Amounts of water available in soil 2. Soil temperature CHART 2 3. Aeration of the soil 4. Concentration of the soil solution 5. Health of roots (disease, insects) 6. Type of plant B. What does a plant do with the water? 1. Less than one per cent is used on photosynthesis (carbohydrates) 2. Transpiration keeps leaf cool 3. Respiration 4. Structural support C. Water use rate factors: 1. Evaporation rate 2. Transpiration rate of plant 3. Cultural practices (turf) 4. Cutting height 5. Nitrogen fertilization 6. Traffic D. Factors affecting water requirements: 1. Stores off-season moisture 2. Ground water table 3. Effective precipitation 4. Water application efficiencies Generally, we refer to peak water use per week for the specific area for which we are designing a system. The water content of actively growing turfgrass is generally 75 per cent to 85 per cent by weight. As little as 10 per cent reduction in water content of a turfgrass may be sufficient to cause death. E. Five main factors affecting plant growth: 1. Genetics 2. Light 3. Temperature 4. Soil moisture 5. Availability of mineral nutrients An initiative of LANDSCAPE ONTARIO 9

10 CHAPTER 3: HYDRAULICS It is important to understand hydraulic principles before beginning an irrigation design. This section includes an explanation of water pressure, friction loss and water velocities. When you understand hydraulics, you then understand the physical properties of water and how they affect the operation of irrigation systems. WATER PRESSURE Water pressure is the force or exertion of water in a piping system. Pressure is created by increasing the height (downward force due to weight) of the water or by using a mechanical booster pump. Pressure is measured in pounds per square inch (PSI). One gallon of water weighs 8.3 lbs. There are approximately 7.5 gallons of water in a cubic foot. Therefore, a cubic foot of water has a total weight of lbs. One cubic foot equals 1,728 cubic inches. When the weight of water in a cubic foot is converted to cubic inches, it weighs.036 lbs. per cubic inch lbs./1728 cu. in. =.036 lbs./cu. in. By multiplying the weight of one cubic inch (.036 lbs.) by 12 inches, it produces a force of.433 PSI for one foot of elevation. The pressure is measured at the base of the 12-inch column, which is the same as a square inch that is 1 foot high. FIGURE 1 When the column of water increases in height, the weight, force and pressure also increases. By multiplying the height of the water by.433, the pressure can be calculated. Therefore, a 100-foot column of water creates 43.3 PSI. FIGURE 2 An initiative of LANDSCAPE ONTARIO 10

11 Static Pressure Static pressure is the amount of water force that is measured in a closed or non-flowing water system. This pressure is measured by attaching a pressure gauge to a hose faucet. With no water flowing in the piping system, static pressure is determined. When there are no hose bibs from which to measure, you can call the local Public Works or Fire Department to provide the static readings. One a level site, the static pressure in the main will be approximately the same as the static pressure at the building. Knowing static pressure is essential before beginning any design. When water begins to flow in a piping system that was once static, the pressure reading on the gauge will drop. The pressure reading with water flowing is referred to as dynamic pressure. FIGURE 3 Friction Loss Friction loss is the reduction in water pressure once water begins to flow through the piping system. Pressure loss occurs when flowing water comes in contact with the inside surface of the pipe and other devices. The rougher the inside surface, the more friction loss it will create. Friction loss may also occur due to increased flow in the pipes. Loss of water pressure occurs when water flows through the following components: Service line Water meter Backflow prevention device Main line pipe Remote control valve Lateral line pipe Fittings Other devices on the system An estimate of the amount of friction loss on the site is required prior to designing the system. An initiative of LANDSCAPE ONTARIO 11

12 Friction Loss (continued) On a residential or small commercial water system, there is typically 20 to 25 PSI loss due to friction from the water main to the last sprinkler. By taking the known static water pressure and subtracting the estimated friction loss, a maximum design operating pressure is determined for the sprinkler heads. For example, if static pressure equals 60 PSI and the estimated friction loss is 20 PSI, the maximum sprinkler design operating pressure should be between 35 and 40 PSI. Friction losses in pipe are calculated using the following information: Type of pipe Size of pipe Length of pipe Amount of water flowing through the pipe Use a friction loss chart to determine exact friction losses for different types of pipe, water meters and gate valves. Friction losses for 100-foot lengths of pipe are listed. To convert friction losses to the exact length of pipe, the loss per 100-foot length is multiplied by a decimal factor of the actual length. Refer to the chart below, ¾-in. Class 200 PVC pipe flowing 10 GPM has a loss of 4.90 PSI per 100 feet. Therefore, 63 feet of ¾-in. pipe has a loss of 3.09 PSI x.63 = 3.09 PSI loss FIGURE 4 Pressure Loss from Friction per 100 feet of pipe (lbs./sq.in.) SDR 21/Class 200 PVC 1120, PVC 1220, PVC 2120 C=140 Flow GPM ½ ¾ 1 1 ¼ 1 ½ 2 2 ½ VELOCITY Velocity is the speed at which water flows through components of a system. Velocity is measured in feet per second (FPS). When designing PVC irrigation systems, it is best to maintain velocities of 5 FPS or less. This reduces the chance of developing surge pressures in the piping system. Velocity information can usually be found on friction loss charts. An initiative of LANDSCAPE ONTARIO 12

13 Refer to the chart below, ¾-in. Class 200 PVC pipe flowing 10 GPM has a velocity of 4.72 feet per second. This is a safe velocity of flow for ¾-in. PVC pipe because it is under 5 FSI. Velocity of Flow (ft./sec.) SDR 21/Class 2000 Plastic Pipe Flow GPM ½ ¾ 1 1 ¼ 1 ½ 2 2 ½ FIGURE 5 AVAILABLE WATER The purpose of this section is to determine the safe amount of water that flows through the water meter and the service line for use by the irrigation system. This section includes a field checklist and calculations used to determine available water. By limiting the amount of water flowing through both the meters and the service line, the friction losses through these components are limited as well. Once the available water is determined, the number of sprinklers that operate from the same valve are then calculated. Correctly calculating available water prevents the system from excessive friction losses occurring in the water meter and service line. A field inventory of components is necessary before beginning. The following should be checked in the field: 1. Meter should be located and checked for size. The size is usually stamped on the side of the meter. 2. The service line from the city main to the meter should be examined for the type of material, diameter size and length of run. FIGURE 6 To determine available water: 1. The pressure loss through the water meter should not exceed 10 per cent of the static pressure. 2. The velocity of water should be maintained below 5 or 7 FPS in the service line, depending on the length of run from the city main to the meter. First, refer to the following chart, Pressure losses through valves, meters and fittings. An initiative of LANDSCAPE ONTARIO 13

14 Calculate 10 per cent of the static water pressure on the site. If the static pressure is 50 PSI, then 10 per cent equals 5 PSI. Find the appropriate WATER METER SIZE at the top of the page. Read down this column to the pressure loss closest to but not exceeding 5 PSI. From this point, go to the far left column (FLOW GPM) and note this flow. FIGURE 7 Pressure losses through valves, meters and fittings Pressure losses through standard water meters Pounds per square inch Flow GPM 5/8 ¾ 1 1 ¼ 1 ½ 2 2 ½ Not standard size Not standard size Prior to determining safe flow through the service line, check the length of service line pipe from the city water main to the connection for the backflow prevention device. If the run is less than 35 feet, the maximum velocity may be 7 FPS. If the run of service line is more than 35 feet long, the velocity should be maintained at 5 FPS or less. This is done to prevent excessive friction loss in long runs of service lines. Next, refer to the following chart, Velocity of flow for the type of pipe used. Locate the appropriate pipe size at the top of the chart. Read down the column to the velocity of either 5 or 7 FPS, depending on the length of the service line. From this point, go to the far left column (FLOW GPM) and record the safe flow through the service line. Compare the safe flow (GPM) from the water meter and the safe flow (GPM) from the service line. Use the lower GPM as the amount of available water that should be used in the design of the system. An initiative of LANDSCAPE ONTARIO 14

15 Velocity of flow (ft./sec.) Type K copper tube FIGURE 8 Flow GPM ½ ¾ 1 1 ¼ 1 ½ 2 2 ½ For example, consider a site consisting of a ¾-in. water meter, 25-ft. long, ¾-in. Type K copper service line and static pressure of 50 PSI. Then, refer to Figure 7. Ten per cent of 50 PSI is 5 PSI. Reading down the ¾-in. meter size column from the top of the chart, the friction loss closest to 5 PSI is 4.6 PSI. The corresponding flow with 4.6 PSI loss in the meter is 17 GPM. This is read from the FLOW GPM column at the left side of the chart. Since the service line is only 25 feet long, the maximum velocity may be 7 FPS. Refer to Figure 8 and locate the ¾-in. column and read down to the point that does not exceed 7 FPS. At 6.22 FPS, the corresponding flow is 9 GPM. This is read from the FLOW GPM column. Since the safe flow through the water meter is 17 GPM and the safe flow through the service line is 9 GPM, the amount of available water is 9 GPM, the lower of the two numbers. An initiative of LANDSCAPE ONTARIO 15

16 Bucket Test Another way to verify available water and working pressure is to conduct a bucket test. This requires the use of a fivegallon bucket and a pressure gauge. Attach the gauge to a hose faucet on the site. Another hose faucet is turned on downstream from the pressure gauge hose faucet. Collect water in the bucket for one minute. While the bucket is collecting water, a reading of working pressure is taken at the pressure gauge. This test tells you the amount of water available, measured in gallons per minute (GPM), as well as the dynamic pressure in the service line and meter. An initiative of LANDSCAPE ONTARIO 16

17 CHAPTER 4: DESIGN SPRINKLER LAYOUT Mastering sprinkler layout guarantees that your system will distribute water evenly over irrigated plant material. This section covers the basic rules and methods used for various layout styles. Irrigation systems with proper head layout produce an even growth rate of plant material. There are many ways to layout sprinklers on a site. Each method will work as long as specific rules are applied to each layout. Many new designers believe there is only one way to place sprinklers on a site. This is not true. Sprinkler coverage must overlap to effectively and efficiently irrigate an area. All sprinklers have an ever-decreasing application of water as the distance increases from the head. Applied water decreases because the total square footage increases farther from the sprinkler. Sprinkler Distribution Curve FIGURE 9 Sprinkler Application A = 314 sq. ft. (6%) B = 942 sq. ft. (19%) C = 1571 sq. ft. (31%) D = 2199 sq. ft. (44%) FIGURE 10 An initiative of LANDSCAPE ONTARIO 17

18 Recommendations for spacing considerations are based on wind conditions. The range of spacing can be from 45 to 60 per cent of the diameter, depending on the wind. The stronger the prevailing wind, the closer the sprinklers should be spaced. In most situations, it is best to maintain a spacing of close to 50 per cent of the diameter of the sprinkler throw, or 100 per cent of the radius. This is often referred to as head-to-head spacing. The rules that must be followed when laying out sprinklers apply to the different layout styles used. The two basic styles of sprinkler layout are square/rectangular and triangular. There are uses and rules for both. Square/Rectangular Layout This layout is well-suited to very defined, geometric spaces, such as small, rectangle-shaped yards, or sites divided by sidewalks and other paved areas. Square/rectangular spacing of heads also protects all borders from overthrow of water by placing sprinklers in the corners and along the perimeters. The remaining sprinklers are then used to fill between the corners evenly. FIGURE 11 The primary rule for square/rectangular layout design is that the recommended distance from one sprinkler to the next should not exceed the radius of the sprinkler. In order to best fit the site, it may be necessary to adjust the spacing. It is, therefore, acceptable to increase or decrease spacing of spray heads plus or minus one foot. Rotary sprinklers may be adjusted plus or minus three feet. If the sprinkler spacing is increased, do not increase the row spacing. Conversely, if row spacing is increased, do not increase sprinkler spacing. For example, if a product catalogue indicates that a rotary sprinkler discharges 3 GPM at 45 PSI with a radius of 38 feet, the recommended spacing from one sprinkler to another is 38 feet. The recommended row spacing is also 38 feet. After finding the spacing distance, it is acceptable, depending on the plant type and wind, to adjust spacing between sprinkler and rows to fit the site. This produces the rectangular shape in the layout. An initiative of LANDSCAPE ONTARIO 18

19 Triangular Layout Triangular layout is a good choice for sites with irregular borders or open areas where overthrow of water is not a problem. The actual coverage from triangular spacing of sprinklers tends to provide better overall coverage versus square spacing. The main disadvantage is the edge of coverage where an oddly spaced sprinkler will throw water beyond the edge of the site. FIGURE 12 Most designers space sprinklers at 50 to 55 per cent of the sprinkler diameter using triangular spacing. The row distance is then calculated by multiplying the actual distance between sprinklers by.866. This provides the recommended distance to the next row. As with square spacing, these distances are recommended, and similar adjustments can be made to suit the size and shape of the site. When using a rotary sprinkler set to 3 GPM operating at 45 PSI, the radius is 38 feet. Diameter equals two times the radius. Therefore, the diameter is 76 feet. By taking 55 per cent of the diameter (.55 x 76 ft.), the calculated distance between the sprinklers is 42 feet. The row distance is calculated by multiplying 42 feet by.866. This distance is calculated to be 36.5 feet. Adjustments can be made to compensate for specific site requirements. Steps for laying out sprinklers: 1. Determine the static pressure of the site. Estimate the friction losses through the system and the design operating pressure of the sprinklers. 2. Measure the site. Break the entire site into smaller geometric shapes for different layouts and sprinklers. Consider plant material and varying watering needs. Determine which layouts are best for the site: square, rectangular or triangular. 3. Determine which sprinklers will be used, the operating pressure and the maximum spacing. 4. Identify the critical line of the site. This is the line of sprinklers that must protect a border such as a street or building. 5. Identify the critical corner of the first line of sprinklers (the combination of the critical line and an adjacent border). This could be the corner of two streets, or the corner of a street and driveway, sidewalk or neighbouring property. 6. Place the first sprinkler in the critical corner, then divide the distance of the critical line to evenly space the remaining sprinklers. If square spacing is used, there should be a sprinkler in each corner with evenly spaced sprinklers in between. If the layout is triangular, the spacing may cause an oddly placed sprinkler at the end. 7. Lay out the next row of sprinklers along a second critical line, such as the edge of a building. Fill in the interior area with evenly spaced rows of sprinklers. Adjust the spacing of the sprinklers and rows to fit the site. An initiative of LANDSCAPE ONTARIO 19

20 FIGURE 13 An initiative of LANDSCAPE ONTARIO 20

21 ZONING A SYSTEM The main purpose of grouping sprinklers together is to regulate the demand from the water source. This section covers the reasons for zoning an irrigation system and proper procedures. By zoning an irrigation system properly, different requirements within the site are irrigated independently. When zoning an irrigation system, the designer groups sprinklers together to run at the same time. In the Available Water section, we covered how to calculate the most efficient amount of water through a water meter and service line. Once this amount is determined, there should never be a demand from any zone on the system greater than the supply capacity. If the demand in a zone is greater than the calculated available water, friction losses will increase throughout the system. This results in sprinklers that perform at less-than-optimum pressure, reduced radius and possible dry areas. All of the sprinklers in a zone are connected with a lateral line pipe. The remote control valve is installed upstream from the sprinklers and connects to the main line pipe. Although flow is very important in determining the number of zones in a system, it is not the only reason to group sprinklers together. Some of the other considerations for zoning include: 1. Grouping similar sprinklers with the same precipitation rate. 2. Separating varying plant material into different zones. 3. Irrigating sloped areas separately from level areas. 4. Zoning shaded areas separately from sunny areas. 5. Creating different zones for varying soil conditions. FIGURE 14 Pipe Routing Once it has been decided which groups of sprinklers will run together, the next step is to route the pipe. Routing connects the heads within a zone on the lateral line pipe and the valves to the water source on the main line pipe. The lateral lines should be placed between the sprinklers and the valve location. It is usually best to run the lateral lines along the rows of sprinklers. This is especially true if the spacing is triangular in layout from a purely hydraulic view. The best pattern of piping looks like an H when designed. Although in real terms, with small gallonage zones (10 gpm or less), this method is not practical. On slopes, the lateral pipe should run horizontally along the contours of the slope, not up and down. This minimizes pressure variations due to elevation changes within the zone. An initiative of LANDSCAPE ONTARIO 21

22 Locating Valves The remote control valves can be placed independently within the site (remote location) or grouped together with other valves (manifolding). Remote location of valves (see Figure 15 below) produces minimal runs of lateral line pipes. This reduces friction loss and also allows the placement of valves in the optimum hydraulic locations within the system. The disadvantages of remote location include difficulty in locating valves on the site after construction, as well as an increased chance of damage to a valve or valve box from maintenance equipment. Manifolding valves require less wire from the valves to the controller location, and the valves are easily located for trouble- equipment. The main disadvantage of manifolding is that more shooting. Usually, the manifolded valves are located outside the landscaped or maintained area. Therefore, there is a reduced chance that damage may be caused by maintenance pipe is needed to run from the valves to the sprinkler locations. Additionally, servicing the manifolded valves becomes difficult if valves are installed too close together. FIGURE 15 The purpose of sizing pipe correctly is to ensure the pipe delivering water to the sprinkler carries the required flow without excessive friction loss. In this section, the steps for properly sizing irrigation lateral and main line pipes are outlined. When pipe is sized properly, the irrigation system flows water at safe velocities with minimal friction losses. There are several methods to determine the proper pipe size. One of the most common is the velocity method. Using the velocity method, the designer limits the speed in each segment of pipe supplying water to the sprinklers. The most agreed upon speed limit of water flow in pipe is 5 FPS. By limiting the speed to under 5 FPS, friction losses are also kept to a minimum. The process of sizing pipe using the velocity method is as follows: 1. Begin at the sprinkler farthest from the remote control valve. Check the gallonage of the sprinkler at the estimated design operating pressure. This information comes from a Product Catalogue nozzle data. 2. Choose the type of pipe needed for the system, for example, SDR 21 CLASS 200 PVC. Refer to the Velocity of Flow Chart. 3. Read down the far left column under FLOW GPM. Follow until the GPM of the sprinkler used in the design of the system, at its operating pressure, is located. To the right of this GPM, locate the smallest pipe size that flows water under five feet per second. 4. Continue adding the GPM from upstream sprinklers to each segment of pipe. Follow Step 3 for all segments. The pipes will increase in size closer to the remote control valves. 5. Valves are sized using the total GPM flow demand from all downstream sprinklers. Refer to a Product Catalogue for valve sizing. Once the valve type is selected, it is sized by referring to the pressure loss charts in the Product Catalogue. As velocity of water is limited in the pipes, there is a limit of allowable friction loss in the valve. FIGURE 16 An initiative of LANDSCAPE ONTARIO 22

23 DESIGN CHECKLIST Design and layout of an underground sprinkler system involves arranging sprinklers, piping and controls together in a system that best fits the conditions of the area to be watered. Therefore, it is very important to secure complete and accurate field information of the actual site. PLOT PLAN General shape of plot or site start with a freehand sketch; obtain dimensions at the job site. Then, using graph paper lay as near the actual shape as possible, keeping close to scale. One inch equals 10 feet (1 = 10 ) or one inch equals 20 feet (1 = 20 ) are the most convenient scales to work with. If lot is irregular in shape, be careful to show shape accurately, showing dimensions for all sides of the area. Give angles, when other than 90 degrees. Sketch house or buildings on plot, as well as all shrubs, trees, hedges, planting beds, walks, drives, parking areas, etc. that will affect the design. MEASUREMENTS Be sure to get sufficient and accurate measurements so that a scaled drawing can be accurately drawn to resemble the site. Always take overall measurements when possible, as well as a series of shorter measurements from one point to another. Check short measurements and be sure they add up to the overall dimensions. Indicate all walks, drives, boundaries, etc. and whether or not overthrow of water on to them is allowable. It is more economical from system first cost standpoint if overthrow of areas can be tolerated. TYPES OF PLANTINGS Indicate on the plot all areas that are to be watered. Indicate all areas with different types of plantings such as roses or delicate flowers that require separate watering control, either by special types of sprinklers or by separate control valves. Note all areas that will require a different frequency of irrigation than the normal turf areas. If shrubs or hedges are present, note height and density, showing fullness of shrubs or trees, which can blow sprinkler coverage. TYPES OF SOIL Note the type of soil on the plot in order to determine the proper rate of application of water, as well as length and frequency of each irrigation. TYPE AND SOURCE OF WATER Indicate the location of the water source. If source is a well and pump, determine the capacity of the well. Note complete data of the pump including motor horsepower, single or three-phase current, pump, capacity, discharge pressure, name plate, type of pump, etc. If available, obtain a performance chart and curve of the pump from the supplier. If source is city water, note the location, length, size and type of service line from the city main to the meter. Obtain the water meter size and the static water pressure in the city main. If possible, make a flow test to obtain available working pressure. An initiative of LANDSCAPE ONTARIO 23

24 CHAPTER 5: INSTALLATION STEP 1: STAKE OUT THE SPRINKLER SYSTEM Take the completed draft design or pace out on the site where each sprinkler head should be placed and put a flag or stake at that location. Different coloured flags can be used for different kinds of heads or valves, or to separately identify zones. Contact the local utility companies for locating and marking any hydro, gas, telephone or cable lines onsite. Try to avoid running lines over these utilities. If you must, then hand dig within one metre from all markings. STEP 2: CONNECT TO WATER SERVICE To get water to your valves, you must attach to your service main line. Provincial plumbing codes may require that a plumber carry out this duty. A backflow prevention device should be installed to protect the water service. Permits may also have to be obtained for the plumbing work. Be sure to include a shut-off valve for the sprinkler line and tag this for easy identification by the end user and any service personnel. Have a blowout valve installed after the backflow preventer (if possible) for winterization purposes. There are devices called through-wall shutoffs that allow water to be turned off inside the building from the outside. The blow-out valve can be connected directly on these devices. STEP 3: PIPE AND WIRE INSTALLATION If the ground is very hard you may want to soak it with soaker hoses along the lines you intend to run pipes. If trenching by hand, a v-shaped trench six to 10 inches deep for single pipe lines is sufficient. For multiple pipe runs in the same trench, you must widen the trench to accommodate them. Wire should be laid beneath the mainline. One wire should be allocated for each valve and an additional wire for the entire system (e.g. a four-valve system should have five wires). It is always a good idea to have extra wires available for expansion or service work. On residential and small commercial systems, an 18-gauge multi-conductor cable with plastic sheathing can be used. See wire charts for maximum lengths of wire runs. If you use polyethylene pipe, a vibratory plow may be used to pull the pipe into the ground. Hand dig your valve box locations and start your pulls from there. In harder soil, pre-digging your head locations can also make the pulling a little easier. Pull your mainline in first and deeper than your lateral (zone) lines. Remember to tape up the exposed ends of your pipes until fittings are attached to prevent dirt from entering the lines. PVC pipe can also be pulled if the lengths are glued together at least three hours ahead of time. Waiting overnight is better. If you have to go under a sidewalk, a tunneler can be made by attaching a high-pressure nozzle to a length of PVC or steel pipe, with a garden hose attached to the other end. Dig a hole on the side where you expect the pipe to emerge after tunneling. Trench back the length of the tunneler on the side you will be pushing from, and keep it level as you use the water pressure to force the pipe under the pavement. An initiative of LANDSCAPE ONTARIO 24

25 Tips on working with different pipes PVC pipe 1. Cut pipe with a PVC pipe cutter. 2. Brush on a primer to clean the pipe surface and the inside of the fitting. 3. Brush solvent (cement) on the outside end of the pipe and lightly inside the fitting. 4. Slip the pipe into the fitting and push all the way in. 5. Hold in place for a count of 10 so the solvent can set. 6. Wipe off excess solvent with a rag. Wait a minimum of one hour before running water through the system, 12 to 24 hours for pressurized main lines. Poly pipe 1. Cut pipe with a poly pipe cutter or sharp knife. 2. Slip a stainless steel clamp over the end of the pipe. 3. Insert the fitting into the end of the pipe, past the barbs. 4. Slide the clamp over the barbs of the fitting. 5. Tighten the clamp or crimp it with the proper tool. To relax poly pipe, expose it to sunlight. Never expose poly pipe to open flame. STEP 4: CONNECT ZONE VALVES TO THE MAINLINE Valves may be grouped together in a manifold. The manifold is made up of a series of tees put in line. Manifolds can be made beforehand with all valve to pipe connections pointed in the right direction. As the valves are installed below ground they should be covered with plastic valve boxes set to grade. A bed of gravel is useful to encourage drainage. Landscape fabric may be cut in sheets and the valves and piping wrapped from below to prevent soil intrusion into the valve box area. Always allow for easy access manual operation of all valves located within the valve box. STEP 5: INSTALL THE SPRINKLER HEADS Install sprinkler heads one zone at a time. Pop-up sprinkler heads should be used in all turf areas and flower/shrub areas where they can be deemed a hazard to foot traffic or a vandalism risk. Dig square holes for all the heads. Square shaped holes are easier for working the pipe fittings on and setting sod back into place. It is recommended to use plastic drop cloths or buckets to store soil for a faster clean-up. Residential pop-up sprinklers should be set just slightly above grade to prevent their pop-up motion from eroding the stem of the sprinkler head. Head may be installed directly to the pipe using threaded risers/nipples, or flexible connections may be made with swing pipe and clampless insert fittings. Flush out the pipe lines prior to installing any nozzles in the heads. Adjust the direction of spray head patterns by ratcheting the stem to aim correctly. Adjust the arc of rotary sprinklers to again match the shape of the area you are watering. Allow for wind by adjusting part circle heads a few degrees larger. An initiative of LANDSCAPE ONTARIO 25

26 STEP 6: INSTALL THE CONTROLLER Install the controller in the garage or basement or location desired by the client. If located outdoors, then the controller must have a built-in transformer and 120V AC power wired directly into it. Indoor controllers may have a plug-in transformer. It is best to have an isolated circuit for the controller, but a low power circuit with only lights will work and will prevent unwanted power surges from upsetting the electronics. Take one wire from each solenoid on the valves and connect them to a common wire (for ease of identification, the white wire is often used). Connect the common wire to the common terminal on the controller. Connect the other wire from the solenoids to their own separate wire and connect these to the station terminals on the controller. Use waterproof wire connectors for all outdoor wire connections. Use wire expansion curls at the valve box locations. Expansion curls are easily formed; simply wrap a minimum of five turns around a 1-in. pipe and then remove the pipe. Curls eliminate wire stressing and also act as lightning protection in the field. TOOL LIST Lawn tools Shovel long handle, D-handle Rake Hand trowel Pick Plastic drop cloth Bucket Pruner Grass seed Irrigation tools Pipe cutter Clamp crimper Rubber mallet Hacksaw Screwdrivers Flags Teflon tape Saddle tools Pressure/flow gauge Pilot tube Voltmeter Wire stripper Pipe wrench Vise grips Socket set Tunneler Wire connectors Propane torch Batteries Flashlight Drill, with drill bits WD40 Gloves Electrical tape General tools Truck Sign Phone Forms Marketing goods Business cards Garbage bags Radio An initiative of LANDSCAPE ONTARIO 26

27 CHAPTER 6: SCHEDULING YOUR IRRIGATION SYSTEM As water becomes an increasingly important natural resource, there are many things that we can do to conserve it. One method is to properly schedule your irrigation systems. Before reducing the watering time, a few things should be addressed. For instance, the sprinkler heads may be operating at too high a pressure, which causes severe misting and wind drift. The sprinkler heads may need to be raised to grade, cleaned, aligned properly to sidewalks, and filters may need to be cleaned. Now that the equipment is functioning properly, let s look at some factors that should affect the irrigation schedule: SOIL TEXTURE FIGURE 17 MAXIMUM PRECIPITATION RATES: INCHES PER HOUR SOIL TEXTURE 0 to 5% slope 5 to 8% slope 8 to 12% slope 12% + slope Cover Bare Cover Bare Cover Bare Cover Bare Coarse sandy soils Coarse sandy soils over compact subsoils Light sandy loams uniform Light sandy loams over compact subsoils Uniform silt loams Silt loams over compact subsoil Heavy clay or clay loam The soil texture affects the rate that water can be applied without having runoff (Fig. 17). The texture and soil depth also determine the moisture holding ability of the soil (Fig. 18). This is because the sandy soil particles have less combined surface area for the water to cling to, than do clay soil particles. This large amount of surface area is why clay soils, once saturated, hold water much longer than sandy soils. FIGURE 18 AVAILABLE MOISTURE* (in the inches per foot of soil depth) SOIL TYPE AVERAGE IN./FT. SOIL DEPTH Sand 0.75 Sandy Loam 1.25 Loam 2.00 Silt Loam 2.25 Clay Loam 1.85 Clay 1.25 *Adopted from Fundamentals of Soil Science by Henry D.Foth, Sixth Ed. For instance, if your soil is poor and you add a soil amendment to it, this is effectively only to the depth that the amendment is mixed into the soil. So, if you have sandy loam soil, adding peat moss and tilling it 6 in. deep, will benefit only the top 6 in. of the soil. Therefore, the moisture holding ability of the top 6 in. of soil will be different than the next 6 in. below it. An initiative of LANDSCAPE ONTARIO 27

28 ROOT DEPTH It is important that we know the approximate depth of the roots, for this in combination with the soil texture, determines the bank of moisture available for plants to draw from. For example, a sandy loam soil, 3 ft. deep, would be able to store 3.75 in. of water in reserve for the plant (3 ft. x 1.25 in./ft. = 3.75 in.). The more moisture that is held in the soil, the longer the plants can survive without irrigation. However, if the root system of the plant is only 18 in., then the available moisture calculation must be based on 18 in. of soil, regardless of the actual soil depth. EVAPOTRANSPIRATION RATE (ET RATE) This is a measurement of how much the plant sweats during the course of the day. The moisture lost is what the plant removes from the bank of moisture available to the root system, until the bank is replenished with the irrigation water. The daily ET Rate for your area may be available from the local weather service (Fig. 19). FIGURE 19 POTENTIAL EVAPORTRANSPIRATION RATES CLIMATE INCHES DAILY Cool Humid Cool Dry Warm Humid Warm Dry Hot Humid Hot Dry The potential evapotranspiration rates are the average maximum ET rates for these climate types. Actual daily ET rates are typically less than these amounts. "Cool" equals under 70 F as an average the mid-summer high. "Warm" equals between 70 F and 90 F as mid-summer highs. "Hot" Equals over 90 F. "Humid" equals over 50% as average the mid-summer relative humidity and "Dry" is under 50%. EFFICIENCY AND UNIFORMITY Efficiency is a measure of both the equipment and the management at a site, while uniformity is related to the systems mechanical performance. For now, let us assume that we have an approximate efficiency of 65 per cent. This would not be a fair assumption if the system in place has severe problems in distributing water or is entirely inappropriate for its task. Properly designed and maintained turf sprinkler systems could be as high as 80 per cent efficient. PRECIPITATION RATE This is a measurement of the average amount of water applied to the landscape, expressed in inches per hour (in./hr.) The precipitation rate for each individual zone should be calculated. For square or rectangular spacing, this formula can be used: Precipitation rate = (GPM of 360 degree sprinkler) x Head spacing (ft.) x row spacing (ft.) RESTRICTED IRRIGATING HOURS OR DAYS Some areas are limited in time in which they are able to irrigate. For instance, school playgrounds water at night, recreational softball fields may water after late evening games, and areas with watering restrictions may be forced to water in a narrow time window. Irrigating days may be limited due to watering restrictions or maintenance on some days. UNUSUAL CONDITIONS These may be conditions such as slopes, extremely shady areas or windy areas. An initiative of LANDSCAPE ONTARIO 28

29 IRRIGATION SCHEDULING Let s combine all of the information we have on soil intake and storage with a modified precipitation rate formula. This is the most important piece regarding scheduling. To achieve.1-in. of water = Generally: Sprayheads Res. Rotors Sports Turf Rotors Spacing x Spacing 16 GPM of 360 degree sprinkler 5 minutes 20 minutes 15 minutes We should look at replenishing the soil moisture level when 50 per cent of the available moisture in relation to the plant root base is used. If average evapotranspiration is.15 in. per day and turf root base is 8 in., soil texture will vary but, unless in a fine sand medium, the soil moisture level is about 1 in. In three days on average, we would have used.45 in. of water. Using the above schedules we would run a sprayhead zone for 22 minutes every third day or a rotor zone for 90 minutes. Best practice would be to split the cycle and apply two to three applications in the day. For sand, the frequency would have to increase because the moisture retention is lower. An every second day schedule would be used to apply.3 in. of water. Again, cycles of.15 in. of water would be the best method to ensure the plants make use of the water entering the soil. Every second or third day is best to optimize plant root development. For newly laid sod, use several cycles daily to relieve plant surface stress and allow the water to soak through to grade. For annuals, since their root depth is minimal, a daily watering schedule should be used. An initiative of LANDSCAPE ONTARIO 29

30 CHAPTER 7: MATERIAL SPRING START-UP PROCEDURES 1. Check all control valves and ensure manual bleed controls are fully closed. 2. Check that flow controls are opened fully and then closed back one complete rotation of the handle. 3. Manually leave open the highest or furthest valve from the point of connection to allow air to escape. 4. Slowly open the manual isolation valve to introduce water back into the piping system. 5. Turn off the manually operated zone valve. 6. Go to the irrigation controller and check that it has kept time. If it has not, reset the time and wait a minute or so to see that it is capable of keeping time. 7. Replace the 9-volt battery in the controller. 8. Run a short cycle through the controller for two to five minutes per zone. Flag any leaks or sprinkler problems. 9. Complete any repairs as required. Ensure that all sprinkler heads have been reset to grade: residential/commercial sprinklers to ¼-in. above the soil grade, sports turf heads at or slightly below grade (if stainless steel). 10. Manually actuate the zones that need service from the controller and check their performance. If all is correct, check the scheduling program and leave the controller in the auto position to begin automatic cycle operations. 11. Test the rain sensor to ensure it will stop when it gets wet. An initiative of LANDSCAPE ONTARIO 30

31 WINTERIZING PROCEDURES 1. Obtain an air compressor that is sized according to the largest pipeline in the irrigation system. For residential sites 125 cfm (cubic feet per minute) is of sufficient size. For sports fields and larger commercial sites, 185 to 350 cfm of air must be created. 2. The air compressor must also have a means of regulating pressure. This is not to be confused with any flow regulator like a manual valve on a discharge hose. Pressure regulation must be maintained at no greater than 80 psi for residential systems and 100 psi for sports fields. In other words, the air pressure should be equal to the standard operating water pressure of the system. Many times, this is accomplished by keeping the rpm s of the compressor set low. 3. Turn off the irrigation controller by putting it into the off position. Do NOT unplug the controller for winter. 4. Turn off the water supply. Make sure that the backflow prevention device has been isolated as they should not have compressed air blowing back through them. If this is the only access point to the system, you may blow through a backflow preventer in the same direction the water flows. 5. Manually open the highest or furthest valve from the point of connection and leave it open throughout the blowout process. 6. Attach the air hose to the irrigation system main line and SLOWLY introduce air into the pipeline. 7. It is recommended to manually turn on each diaphragm control valve in sequence, opening the next valve first before closing down the valve that has been blown out. Each valve should be opened at least twice to ensure that all air in the piping system has been evacuated. Watch for the water to fog and vanish before opening the next valve. 8. When the system has been entirely blown out, shut off the compressor, disconnect the air hose from the piping system and close off any manually opened valves. 9. Winterize the backflow preventer in accordance with manufacturer s recommendations. This usually means opening the test cocks and draining the valve while leaving the test port valves in a half-open position over winter. 10. If a pump is involved, drain the pump in accordance with manufacturer s recommendations. Store pump in a climate-controlled environment, if possible. An initiative of LANDSCAPE ONTARIO 31

32 CHAPTER 8: SERVICE TROUBLESHOOTING TROUBLESHOOTING METHODOLOGY To develop a troubleshooting methodology, we must visualize the six major components of any automatic sprinkler system and how they relate to each other. Every automatic system has: A pressurized water supply An automatic controller Field wiring between the controller and valves or tubing, if the system is hydraulically controlled Automatic zone control valves Sprinklers to distribute the water The pipe and fittings necessary to complete the system The usual field conditions experienced when one of the system s components fail are very often signs of plant stress or death. These symptoms might be localized or they might be system wide. Other clues are dry pavement when you would expect to see signs of earlier scheduled watering, or soggy, even eroded areas that indicate excessive watering. STEP 1: CONFIRM WATER SUPPLY The first step is to verify that the system is pressurized. Locate a zone control valve that does not respond to a start cycle from the controller. All automatic valves have some means of manual operation. Find this bleed device and open it. This will relieve the hydraulic pressure on top of the valve s diaphragm or piston and allow the upstream water pressure to open the valve. If the sprinklers are not activated, check the flow control handle. The flow control limits the amount of valve opening and is used to fine tune the system by adjusting the downstream pressure. It may have been cranked down so the valve ca not open. If the valve operates manually, move onto the second step since you know the system is pressurized. However, if it does not operate manually, backtrack to find where the water supply has been interrupted. Check the backflow device, but not at the zone control valve; there is probably a master valve between the two. Track it down and repeat the manual bleeding process. If there is no water at the backflow prevention device, move upstream and verify that the isolation valve and/or water meter are open. STEP 2: AUTOMATIC CONTROLLER The next step is to verify that the controller is operating properly. It has been estimated that 90 per cent of system failures can be traced to the controller, and that 90 per cent of controller problems are programming errors. This means that there is an 81 per cent chance that the system failure is the result of HUMAN ERROR in programming the controller correctly. This being the case, first check the controller program: - Rain or system switch on? - Time set on individual stations? - Stations switched in an on or auto position? - Start cycle times set? - Correct day and hour set? An initiative of LANDSCAPE ONTARIO 32

33 A manual start should now activate the system. If not, confirm that there is power to the controller. Check to see that fuses are good and reset any circuit breakers. If the circuit breaker kicks out during an irrigation cycle, disconnect the field wires at the controller. Reset the circuit breaker and start another cycle. If it does not kick out now, the problem (probably a short) is in the field wiring; if it does kick out, the problem is definitely in the controller. Isolate and repair or replace the defective part. A Volt/Ohm multimeter is an inexpensive must for troubleshooting. Set to the resistance scale, you can verify the integrity of coils, motors, relays, fuses and simple circuits by testing for continuity or a low ohms resistance reading. To check voltage, you must set the meter to the voltage scale. Always set the meter to a higher scale than you expect to read. Set to a lower scale if the needle moves so little that the reading is difficult to interpret. Reading voltage on any other scale will cause damage to the meter and maybe you! WARNING! ASSURE 120 VAC POWER SOURCE IS DISCONNECTED PRIOR TO MAKING WIRE CONNECTIONS. FAILURE TO COMPLY MAY RESULT IN SERIOUS INJURY AND/OR EQUIPMENT DAMAGE DUE TO ELECTRIC SHOCK HAZARD. ALL ELECTRICAL COMPONENTS AND INSTALLATION PROCEDURES MUST COMPLY WITH THE NATIONAL ELECTRICAL CODE AND LOCAL CODES AS THEY APPLY Most controllers operate on 120 VAC. Carefully reading the input voltage, you should read between 105 and 130 VAC. If not, determine where the power has been interrupted. When you check after the transformer, you will read between 21 and 26 VAC if the transformer is functioning properly. Power specifications are usually found on the controller cabinet or door. Satisfied that you have input voltage, the next step is to check for output voltage. Set time on a station, activate a manual start and read output from the terminal strip. A valve must be hooked up so there is a load on the circuit, or you may get a false reading. If your check shows no continuity, determine if there are rain or freeze gauges in the system before you move onto step three and troubleshoot the field wiring. Rain and freeze gauges are devices that interrupt the 24 VAC output to the field by breaking the common wire leg of the 24 VAC circuit. If such a device is activated, you will not have continuity through the field wiring. STEP 3 FIELD WIRING/SOLENOID: We have checked the voltage output at the terminal strip with the voltmeter. We will now check the resistance at the terminals with the ohmmeter. We are about to learn some very helpful things about the faulty circuit without ever leaving the clock! With the power off, reconnect the common wire to its terminal and clip one probe to it. Touch the other probe to the control wire terminal and record the resistance. If the ohmmeter reads maximum, initially, infinity, we know there is an open somewhere in the circuit. If the reading is lower than a similar sound circuit, 8 Ω to 12 Ω, then we know we have either a partially shorted solenoid or a multi-valve station. If the reading is much lower than a similar sound circuit, 1 Ω to 5, we know that we have a full or total short in a solenoid and that we are reading only the resistance in the wires. An initiative of LANDSCAPE ONTARIO 33

34 If we get a higher than normal reading, over 60 Ω to 100 Ω, we have a partial connection. This indicates loose splices, nicked wire, skinned insulation, long runs or too small a gauge. These are the reasons valves will not open. Our troubleshooting methodology has already eliminated all the non-internal reasons for valves not opening: 1. No water pressure First item we checked. 2. Flow control closed Already checked. 3. Controller malfunction Confirmed operation. 4. Faulty field wiring Checked integrity. 5. Faulty solenoid Also checked. 6. Plugged discharge path The most common INTERNAL reason for the valve not opening. *First partially disassemble the valve by removing the solenoid after turning off the water supply. Be careful not to lose the O-ring, solenoid plunger and plunger spring. The blockage may be found at this point. If the valve still does not operate after reassembly, completely disassemble and clean all internal passageways. CAUTION Avoid using any tool that may enlarge the internal passageways of the valve. Their sizes are engineered, and changing them can cause the valve not to operate properly. Let s consider the reasons why valves will not clear: 1. Controller malfunction Check for power and programming errors. 2. Debris between diaphragm and seal Common reason not to close. 3. Plugged discharge path Disassemble and repair. 4. Ruptured diaphragm Disassemble and repair. CAUTION If debris is holding the diaphragm open, cranking down on the flow control to close the valve could ruin the valve seat and require a complete valve replacement, or you might end up with a slowly weeping valve. If you need to shut the system down, use the shut-off valve at the backflow device or the system isolation valve. STEP 4 SPRINKLER HEADS: Because of the great diversity of sprinklers, our troubleshooting methodology will consider only problems common to all sprinklers. Check with your distributor for service information on the particular sprinklers on your project. Sprinklers should be operated and visually checked. Many landscaping dollars are lost each year, and a terrible amount of water is wasted because sprinklers are not serviced on a regular basis. One of the most common sprinkler problems is a sprinkler whose nozzle or rotor is clogged with debris. These sprinklers need to be disassembled, usually from the top, cleaned and reassembled. Most sprinklers either come with, or have available, plastic nozzle screens. Sometimes these do not get installed. Having them onhand is helpful so you can install them when sprinkler disassembly is necessary. If clogged nozzles are a recurring problem, a filter installed near the point of connection will prevent debris from reaching the sprinklers and save many hours of labour. Too much pressure, or not enough pressure, at the sprinkler are also common sprinkler problems. Each type of sprinkler is designed to operate within a range of pressures (detailed in the manufacturer s catalogue). Too much pressure at the nozzle causes misting, which reduces the radius of the sprinkler, making the pattern prone to wind disturbance and distorts the sprinkler s distribution. A valve with flow control can be adjusted to dissipate constant excess pressure. A pressurized regulating valve will maintain a constant downstream pressure even with fluctuating high pressures. Not having the minimum operating pressure at the sprinkler causes dry spots around the head or midway within the radius, because the water stream isn t atomized sufficiently for efficient distribution. An initiative of LANDSCAPE ONTARIO 34

35 System pressure might be increased by opening up any pressure regulators and valve flow controls, or reprogramming the controller to start earlier in the morning to take advantage of higher mainline pressures. If sprinklers are over-spaced, or the pipe undersized, there are not any simple solutions. You might consider a booster pump to bring the pressure up to the high end of the nozzle specifications as a means of improving performance. The system must be analyzed prior to adding a pump to ensure that damage will not result to any of the system s components. STEP 5 PIPE AND FITTINGS: Problems with this component of the system usually involve a break and require a repair. There are several devices available that simplify this operation. A plastic suction or bilge-type pump available through an irrigation supply store is very valuable in getting rid of water and mud at the site of a break. Ratchet or tubing type pipe cutters eliminate the small pipe particles produced by saws that do such a good job of plugging valves and sprinkler nozzles. Riser assemblies make the connection between the piping and the sprinkler. Flexible riser assemblies allow the sprinkler to be positioned easily and protect the piping from breakage. Flexible hose-like Funny Pipe make excellent risers and make it easier to install sprinklers in tight locations. TROUBLESHOOTING HYDRAULIC SYSTEMS Review Hydraulics in appendix. The troubleshooting sequence is the same for a hydraulic system as it is for an electric system: 1. Confirm supply water is available at adequate pressure. 2. Confirm that controller is programmed and functioning correctly. 3. Control tubing intact. 4. Valve operating correctly. The main troubleshooting difference in our hydraulic system is confirming the integrity of the control tubing. Blocked control tubing, either at the valve or the controller, is often the cause of valves not opening. Valve failure is close to very often due to leaking control tubing or leaks at the valve body. Check the tubing at all connections and look to see if any cultivation or digging has severed the control tubing. This systematic troubleshooting approach takes us step-by-step through each of the system components, starting with the system component with the highest probability of being the source of the system s non-operation and working to the component with the lowest probability of being the problem. Today s landscaping investments demand irrigation professionals who can efficiently troubleshoot problems and effectively manage the irrigation system. With a systematic approach, you can quickly diagnose the problem, its location, and quickly get the system up and running. An initiative of LANDSCAPE ONTARIO 35

36 Plastic Diaphragm Valve (Electric) The electric model valves are solenoid actuated and held in the normally closed position by internal water pressure. The electric valves are designed for clean water systems. Closed position Irrigation water, metered through the diaphragm orifice, fills the diaphragm chamber causing internal pressure to build. The pressure exerted within the chamber holds the diaphragm assembly firmly against the valve seat, preventing water flow through the valve. The diaphragm pin helps prevent debris from clogging the orifice as the diaphragm moves to open and closed positions. Open position The valve solenoid, when activated by 24 VAC from the controller, draws the solenoid plunger away from the discharge port, relieving water pressure from the diaphragm chamber. The irrigation water pushes the diaphragm assembly away from the valve seat allowing water to flow through the valve. The valve will remain open until the controller discontinues. An initiative of LANDSCAPE ONTARIO 36