Valves. Controllers. Valves Two Types

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1 Hydraulics Taking the Irritation out of Irrigation My plants are getting irrigated, so I m all set, right? Marcus Duck Academic Advisor, Instructor & Program Coordinator MSU s 2-year Horticulture Programs in East Lansing Hydraulics Hydraulics study of behavior of fluids at rest (static) and in motion (dynamic) Relationships between flow (gpm), velocity (fps), and pressure (psi) Crucial to determine pressure losses in pipe, fittings, valves, etc. Static Pressure water at rest Created by elevation change or pump A column of water 1 ft high = psi Every 1 ft elevation change = change of psi Pushing water up hill, subtract psi Water going downhill, add psi Dynamic Pressure water in motion Always find static psi losses or gains first Then dynamic psi losses due to movement Friction loss occurs due to turbulence created by moving water 4 factors affect friction losses in pipe Friction Loss in Pipe 1. Velocity 5fps in PE / PVC; 7fps in metal 2. Inside Diameter (i.d.) smaller creates more psi loss due to increased turbulence 3. Roughness C rating of pipe 4. Length 1

2 Nominal Size Avg. ID Pipe OD Avg.Wall Min. Wall Irrigation Association Friction Loss Chart 2008 CLASS 200 PVC IPS PLASTIC PIPE ASTM D-2241 (1120,1220) SDR 21 C=0 PSI Loss Per 100 Feet of Pipe Class 3 1/2" 3/4" 1" 1 1/4" 1 1/2" 2" 2 1/2" 3" 4" 6" Flow Velocity PSI Velocity PSI Velocity PSI Velocity PSI Velocity PSI Velocity PSI Velocity PSI Velocity PSI Velocity PSI Velocity PSI GPM FPS LOSS FPS LOSS FPS LOSS FPS LOSS FPS LOSS FPS LOSS FPS LOSS FPS LOSS FPS LOSS FPS LOSS Funny pipe don t use too much! Controllers Types of controllers: 1. Electromechanical 2. Hybrid 3. Central Control 4. Hydraulic (water tubes instead of wire) Tech. constantly changing; stay up-to-date Valves Used b/c not enough water to run everything at one time Open & close by signal from controller Valves buried under ground in plastic valve boxes USE THEM Valves Two Types 1. Hydraulic, Normally Open Small water tube from controller to valve Water under pressure = valve closed Controller allows psi to drop = valve open Good for dirty water systems Hole in tube = valve stays on 2

3 Valves Two Types 2. Electric, Normally Closed: Controller sends 24V to solenoid on valve lifts plunger off to open port. Water psi on top of diaphragm drops valve opens Wire problems = valve won t open Pipe PVC (main & laterals) Rigid, installed by trenching Slip fittings; primer + glue Pipe Polyethylene (small mains & laterals) Flexible, installed with a puller Barbed fittings; clamps Copper Service line; plumber install? 3

4 Spray Patterns (Arcs) Full circle (360 ) Half circle (180 ) edges, borders, etc. Quarter circle (90 ) Variable Arc Nozzles (VANs) - 1º to 360º Rotors use those that allow arc adjustments Spray Patterns (Trajectories) Standard 30º to 40º above horizontal Low or flat 10º to º High Greater than 40º Fixed / Sprays 75% DU = excellent; 60% DU = good 30 psi optimum psi for most heads High PR (1 2.5 /hr); use short cycles Strip nozzles narrow turf strips Flood heads small spaces, single plants Nozzles easily interchanged Fixed / Sprays Fixed Nozzles = to 17 max radius Fixed or Rotor? Rotating Nozzles = 8 to 30 radius Rotors 80% DU = excellent; 70% DU = good Mid-size Rotor = to 30 radius Rotor = 25 to 40 radius 4

5 Micro Irrigation Drip, micro sprays, bubblers FILTERS! Distribution Curves A = 314 ft 2 (6%) B = 942 ft 2 (19%) C = 71 ft 2 (31%) D = 2199 ft 2 (44%) Overlap Determination Most heads have triangular shaped distribution curves Head to Head = Even distribution of water (DU) & balanced precipitation rates (PR) Overlap Determination Manufacturer specs = max allowable spacing This is a reference number only It applies to dead calm situations & should not be used in an actual design Always anticipate a minimum 4 MPH wind when spacing heads Overlap Determination You can increase or decrease spacing of fixed heads 1 foot and rotors by 3 feet Distribution uniformity (DU) goal when performing head layout in design Don t want wet or dry spots 5

6 Precipitation Rates PR - speed at which an amount of water is Precipitation Rates Rates vary according to sprinkler type: applied Used to estimate run times Used to prevent wet or dry areas If not known usually over watering occurs Precipitation Rates High PR = runoff on soils with low IR Use shorter cycles Total run time limited by total GPM available at the source Low PR systems cost less: Fewer valves per acre Fewer controller stations per acre Water supply is 30 GPM 2 min ea 1 30 min Radius Adjustment and DU Distribution Uniformity (DU) measures how evenly water is applied Sprinkler designed to operate well at a given radius Adjust too much = DU reduced = dry spots PR is avg amount of water over an area Does not account for DU Radius Adjustment and DU Fixed Spray Heads: Adjustment screw changes radius and internally changes GPM Adjustment screw radius and GPM are adjusted here, before water leaves the nozzle 6

7 Radius Adjustment and DU Rotors and Impact Heads: Adjustment screw, flap, or pin externally disrupts spray radius w/o change in GPM Radius Adjustment and DU NEVER reduce radius of spray on rotors to less than 75% of manufacturer s radius Example: 33 ft. x 75% = ft. Matched Precipitation Rates Matched Precipitation Rates Matched Precipitation Rates Fixed nozzles were 1 st to -T-PC Options Available 180 -H have MPR Rotating / precision nozzles are also designed for MPR Specifications Dimensions 3 8 (60mm) Lawn Pop-up: (5mm) High-Pop: 16 (405mm) Operating Specifications Lawn Pop-up and High-pop: GPM (2-28 LPM) Shrub (COM): GPM (7,8-24,0 LPM) Lawn Pop-up: 3 ¾ (95mm) High-Pop: 11 ¾ (298mm) ' Series with 28 Trajectory Black Lawn Pop-up Arc Desc. and High-pop: psi GPM ¾ (20mm)!! Shrub: ½ to ¾ (13-20mm) elevation change T H-PC Omni Nozzle Cover 1.64 (Use 1.42 with Part No. 300-) -TT High-pop 50 Omni Nozzle Cover (Use w/part No. -TT-PC ) Rotor Plug elevation change F (standard on high-pop 50 models) F-PC Warranty 340 Series: 300- Omni Adjustable-radius Nozzle Performance Chart US psi Radius Precipitation Rate* ! " GPM Matched Precipitation Rates Rotors: 340 Series Lawn Pop-up 50 psi US 27 Nozzle Max. Ht. of Spray 01 4' 10" 02 5' 1" 03 5' 11" 340 Series: Shrub w/com (360 Arc Disc) (Model Nos COM) US Nozzle psi 340 Series GPM Radius Omni (Min) Omni (Min) Omni (Max) Omni (Max) Single nozzle type gives MPR regardless of arc 340 Series: Fixed-radius Nozzle Performance Chart US Nozzle psi Radius Precip. Rate* ! " GPM *! Precipitation rates are for triangular spacing, shown in inches per hour, calculated at 50% of diameter. " Precipitation rates are for square spacing, shown in inches per hour, calculated at 50% of diameter. All performance specifications are based on the stated working pressure available at the base of the sprinkler. Radius shown in feet. Data based on 360. Low gallonage. 340 Series Multi-Stream Rotor Model List Model Description Lawn Pop-up w/plastic Arc Disc Tree Shrub w/plastic Arc Disc Tree Shrub w/check Valve and Plastic Arc Disc Tree 12 (300mm) Pop-up w/plastic Arc Disc Tree Specifying Information 340 Series Multi-Stream Rotor 7

8 Super 800 Standard Nozzle Performance Data Matched Precipitation Rates Rotors (cont.): Most rotors use nozzle sets The designer MUST select correct nozzles to achieve MPR Range between nozzles w/n a set = ± 10% Precipitation Rate Nozzle psi GPM Radius (in/hr)!""""(in/hr) # Super 800 Low-angle Nozzle Performance Data Precipitation Rate Nozzle psi GPM Radius (in/hr)!""""(in/hr) # * Radius shown in feet. Data based on mation Super Radius shown in feet. Data based on 360. *Pre-installed nozzle. 4 Steps of Head Layout Block off into geometric shapes 1. Block off into geometric shapes by types of heads to be used 2. Start in corners 3. Work along the edges 4. Fill in the middle Zoning Rules Like With Like Flow limits maximum zone size Physical dimensions Shrubs & turf = different water needs Sun & shade areas = different water needs Fewest zones possible to minimize costs 8

9 Zoning Rules Like With Like Rotors with Rotors Fixed with Fixed Drip with Drip Easier to design and schedule Better calculations for water distribution, precipitation rates, etc. Zoning Rules Like With Like Runoff on sloped vs. flat areas Zoning Rules Like With Like PSI loss on sloped vs. flat areas Winterization Tips Usually by Nov 1 st BFPD most critical: Exposed to elements Leave valve at 45º Fully open or closed allows moisture accumulation Winterization Tips Blowing out system: Compressed air Never exceed 60 psi damage or melt Close BFPD don t forget 45º afterwards Farthest zone 1 st Never more than 5 minutes = melt rotors 9