2 Trenching for turf system mainlines and laterals Lines trenched 2 ½ feet deep will require no special winter maintenance. Average freezing depths are about 5 inches in far SE OK and 15 inches near the Kansas border. Extreme freeze depths are 10 inches in SE OK to nearly 30 inches in the Panhandle. Lines at shallower depths should have low pressure drains or else be cleared with compressed air in extremely cold weather.
3 A 3-inch mainline supplying a 2 ½-inch lateral Here a 2 ½-inch lateral line branches of a 3-inch mainline. Since valve-in-head sprinklers are being used in this project, no valves are located at the branching point. If smaller heads were being used, a solenoid valve would be located where the lateral joins the mainline, and all the sprinklers on the lateral would be operated as a single zone. Note the purple stains in the joints. That is residue from the PVC primer which is used to clean and soften the pipes and fittings so the glue will make a better solvent-welded joint.A 3-inch mainline supplying a 2 ½-inch lateral
4 Swing arm plumbing for large turf sprinkler head A tee is located at the site of each sprinkler head. A reducing tee is normally required to step down from the lateral size (2 ½ inches in this case) to the size of the sprinkler swing- arm assembly (1 ¼ inches here). The swing-arm joints are threaded with neoprene O-rings to seal the joint while allowing the connections to pivot for alignment and height adjustment.
5 A plumbed sprinkler head ready for wiring and backfilling Here is a plumbed sprinkler head, ready for wiring and backfilling. Note the hand-excavated area to the side of the lateral line trench for the swing-arm and sprinkler head.
6 Hunter® valve-in-head turbine driven rotor sprinkler P= 70 psi qs=50.5 gpm Dw=170 ftP= 80 psi qs=53.5 gpm Dw=176 ftP= 90 psi qs=57.4 gpm Dw=180 ftP=100 psi qs=59.5 gpm Dw=184 ft#53 (53/128”) range nozzle + #24 (3/16”) spreader nozzleLarge valve-in-head sprinklers are frequently used for large, open expanses of turf, such as fairways. They can be used on spacings of feet or more and still achieve uniform coverage. The entire lateral network on a fairway can be pressurized and the controller can then sequence through individual sprinklers or groups of sprinklers, at the maximum flow capacity of the water supply, until the entire area is adequately irrigated.At 90 psi these Hunter® heads will deliver 57.4 gpm over a wetted diameter of 180 feet. With a 50% overlap that allows a spacing of 90 feet. On a 90-ft triangular spacing that would equate to a 0.79 in/hr application rate, or a 0.68 in/hr rate on a 90-ft square spacing.
7 Valve-in-head sprinkler Here the valve assembly is visible on the side of the sprinkler head. To reduce the power requirement to operate valves, and thus the size of wires required to supply the electric current to operate them, most valve-in-head sprinklers and large control valves are diaphragm valves. These use a small electric solenoid valve to let pressurized water from the water supply operate the main on-off valve. The small tubing running down the side of the sprinkler head carries the water to operate the main valve.Valve-in-head sprinkler
8 Wire to connect controller to valves Individual “Hot” wires (Red; typically 14 AWG) to each valveA single “Common” wire (White; typically 12 AWG) for all valvesThe wire to carry the operating current from the controller to the individual zone or sprinkler head valves must be large enough to carry the required current the distance between the controller and the valves without too much voltage drop. Most modern solenoid valves are 24-volt AC. Alternating current can travel longer distances without excessive voltage loss, however it can present the hazard of electric shock. A low voltage of 24-volts eliminates the shock hazard, and the need for enclosing wires in conduits for protection, while still minimizing the voltage drop of longer distances, allowing wire sizes to stay small enough to be economical. Each valve will have a single “hot” conductor running from its individual circuit on the controller to operate it. Normally a #14 for long runs or a #16 wire for short runs is adequate for the hot wire, which is usually red in color. A single “common” wire for all the valves in a location is used for the return leg of the circuit. Since more than one valve may be in operation at one time, the common wire is usually larger to carry the heavier current load. The common wire is usually white in color.
9 Gel-filled waterproof connector cover for buried wire splices Electrical connections are made with wire nuts. To protect the connections from short circuiting in wet soil, or from cathodic corrosion due to dissimilar conductor metals, the connection is encased in a capsule filled with a waterproof silicon gel. The capsule also provides some strain relief on the connection.
10 Bundling extra wire to ease future repair operations It is usually advisable to loop some extra wire after the connections are made. A little extra conductor length eases future repair jobs and may eliminate the need for splices if the conductors are damaged during excavation.Bundling extra wire to ease future repair operations
11 Newly back-filled turf head The completed installation should be flush with the soil surface if direct seeding will be used to establish the turf. The head may protrude an appropriate amount to be flush with the turf surface if sod is going to be laid on the site.Newly back-filled turf head
12 Low pressure drain for lateral lines Lateral lines for home turf installations are frequently installed at shallower depths (12-18 inches). Consequently, these lines are fitted with low-pressure drains. These drain valves will close automatically once the water pressure in the lines reaches 10 psi, and will remain closed as long as the system pressure is maintained. Once watering ceases and the pressure drops below 10 psi, the valves spring open and water will drain from the lateral by gravity. The valve should be located at the lowest point on each lateral line. One valve per lateral is normally sufficient.
13 Adapter for “Funny Pipe” riser and low pressure drain The small sprinkler heads used for home turf systems can be supplied adequately with a flexible Polyethylene tubing riser, which is much less expensive than a swing-arm riser. Here is a “funny pipe” connector attached to a PVC lateral, ready for connection to the riser.
14 Small turf head with “Funny Pipe” connector attached A small pop-up turbine rotor turf head with a “funny pipe” connector, ready for connection to the lateral line with a flexible polyethylene riser.Small turf head with “Funny Pipe” connector attached
15 Home Landscape Irrigation 4.6Home Landscape Irrigation4.6Here is a typical home lawn irrigation layout. The number of zones in a home system is dictated by both the layout of the yard, the types of vegetation, and the size of the water supply. Here, larger turbine rotors or impact heads irrigate the large open expanse of the back year in two zones with 3 heads each (two 90° part-circle heads, and one 180° part-circle head) on a 40-ft x 45-ft spacing.In the front and size yards, smaller spray heads irrigate smaller areas with a layout on 12-ft to 15-ft spacings, using a combination of full and part-circle heads to cover the area adequately while keeping water off the house, driveway and street. No zone requires more than 15 gpm to operate.
16 Separate meter for home landscape irrigation system Irrigation rate for city water (no sewer charge)It is usually advisable to go to the expense of having a separate water meter installed for a home sprinkler system. In most municipalities charges for sewage treatment are proportional to water consumption. A sprinkler system on a regular household meter would then be paying not only for water used but also for sewage treatment on wastewater that was not going into the system. The additional expense of installing a new meter is quickly recovered in the savings in water cost. Also, the operation of the sprinkler system will not interfere with household water use.Meter Size, inches 5/8 ¾ 1Maximum Capacity, gpmRecommended Capacity, gpm
18 Golf Course Irrigation Zones Different zones because of differences in-Turf varieties: bent, bermuda, etc.Soils: sand-based greens, native soil fairwaysTraffic load: tee boxes, greens, walk-up areasCanopy maintenance: fairways, roughGolf course turf irrigation zones are set up based on variations in turf type, soil type, traffic load, and variations in canopy maintenance within turf species.
19 Golf Course Irrigation Zones - Putting Green Zone-Tee Box ZoneGreens, with coarse soil types for rapid drainage and common use of cool-season species require frequent, small irrigation applications.Fairways, with bermuda grass on native soils would be irrigated less frequently with larger application depths.Tee boxes and the walk up areas to greens, with the heavier foot traffic may be irrigated more frequently than fairways.Rough areas may be irrigated as often as fairways, but with lesser application depths because of incomplete coverage.- Walk-up Area Zone- Fairway Zone
20 Lateral Line Layout for Parallel Fairways (2 conventional sprinklers per valve)Mainline SupplyValveWater Flow
21 Looped Supply Lines on Parallel Fairways (Valve-in-Head Fairway and Tee Box Sprinklers)(Conventional Green Sprinklers)
22 Fairway Runoff Research Plots at OSU Turf Research Farm
23 Effect of Slope and Sprinkler Leveling on Coverage Sprinkler axis perpendicular to ground slopeSprinkler axis vertical
25 Adjustment of Watering Time Watering time can be increased or decreased according to prevailing water use conditions (ET). ET can be taken from a weather station on site provided by the supplier, or taken from some generic source (eg., Mesonet). Adjustments can be system-wide, or for any subset of zones within the system.
26 The terminology and capabilities of each controller/software package will vary. On-the-job training (RYFM) and/or a training seminar from the manufacturer will be necessary.
27 Irrigation TimingThe ON/OFF timing of the irrigation system must be coordinated to avoid interference with play, mowing, and other maintenance while not exceeding the capacity of the water supply.
28 Time and Flow Rate Constraints (Q t = kv A d) Most controller software will allow you to program in constraints of available water flow rate. Once you program the on time for each zone, the controller will sequence the zones to maintain total flow within the constraint. A graphical output will show the time required to determine if irrigation will be completed within the available time.
29 Record KeepingMost controller software can also be programmed to maintain a history of on times, depths applied, gallons pumped, etc. These data can be extremely helpful in budgeting, troubleshooting and other management decisions.
30 Antenna Transmitting Signals from Main Controller to Satellites
32 Electronics Linking Satellite Controller to Main Controller
33 Connections from Zone Valves to Satellite Controller 24-volt AC hot wires from each zone valve on 3 holesCommon wires from 3 holes
34 Completed valve-in-head sprinkler installation ready for back-filling The completed installation with excess wire bundled neatly below the head reduces the risk of conductor damage or separating connections during backfilling.Completed valve-in-head sprinkler installation ready for back-filling
35 Valve-in-Head Sprinkler Components Housing/Case Main Nozzle RotorCoverSpreader NozzlesWater supply tube for valve operationSolenoid
36 Large Turbine-Driven Rotor Sprinkler for Fairway Irrigation
37 Diaphragm Valve (24-v. AC) to Control a Multiple-Head Zone
38 Electrically Operated Diaphragm Valve Cutaway SolenoidSolenoid plungerPort carrying pressurized water to inflate diaphragmPort allowing water trapped behind diaphragm to be ventedOptional flow control screw adjustmentDiaphragmValve seatSpring
39 1-inch Electric Diaphragm Valve w/ Flow Control Manual flow control adjustmentInternal/external bleed port24 VAC solenoid1-inch Electric Diaphragm Valve w/ Flow Control
40 24-VAC SolenoidAuto Manual Drain Bleed Port ValveValve Cap DiaphragmSolenoid Plunger & Drain Port SealPressurization PortSpringValve BodyDrain PortValve SeatWater Flow
41 Cap Underside Diaphragm TopsideManual External Bleed ValvePressurization PortAuto Bleed PortCap Underside DiaphragmDiaphragm Valve Seal
47 60-HP Holloshaft Motors on Vertical Turbine Pumps
48 Electric Pump Control Panel A complex control panel to operate and protect an electric irrigation pump may include:over-current protectionphase protectionlightning arrestorscomputerized control for:soft startreduced speed operation
49 Computerized Motor Control Computerized motor control allows soft starts, which reduce the current flow when the motor rotor is not yet up to full speed.Computerized control can also artificially alter the frequency of the electric supply, allowing the motor to operate at speeds other than nominal synchronous speeds (3600, 1800, or 1200 RPM).
50 Computerized control panels can log performance data
51 Pulse-count Water Meters Provide Feedback to Irrigation Controllers Signal wire connected to irrigation controllerMagnetic pick-up counts meter revolutionsPaddle-wheel water meter
52 Pressure Regulating Valve Controls Output Pressure from Pump Station
53 Pressure GaugeSchrader ValveSchrader Valve FittingSome diaphragm valves are equipped with a Schrader valve that will allow measurement of pressure in the valve during operation
54 Pitot Gauge for Measuring Sprinkler Outlet Pressure
55 USGA Putting Green Profile TitleistRoot Zone MixCoarse grained material(loamy fine sand – fine sand)(Hyd. Conductivity > 6 in./hr)Intermediate Layer(coarse sand – fine gravel)Crushed StoneNative Soil12 in.4 in.8 in.Drainage Lines
56 Green Irrigation (USGA Specification Greens) Flushing once per weekHeavy irrigation that wets entire profile depth and produces leachate to the drainage systemHand watering dailyConcentrate on areas that dry out quicklyShoulders of elevated greensHigh spots in undulating greensLate summer (August)Increase flushing schedule to every 6 days or even every 5 days
57 Elevated portions of greens will dry out quicker Hand watering will supplement irrigation system watering on areas which dry out more rapidly due to elevation contours
58 Fringe areas of elevated greens will dry out more quickly
59 Backflow PreventionProtects water source from contamination by non-potable water in case of unexpected pressure loss in the system. Required by plumbing code in the case of permanent sprinkler systems. Required by federal law on irrigation systems which apply fertilizer and pesticides (chemigation systems).
60 Backflow PreventersGooseneck pipe loop with Pressure Vacuum Breaker (PVB)Reduced Pressure Zone device (RPZ)Double check valve (Not approved for public water systems)
61 2 ft min. above highest outlet Gooseneck pipe loop w/ PVB backflow preventer