Residential Sprinkler System Design Handbook

Introduction

This booklet is intended for designing and installing single-family residential sprinkler systems. It is structured for easy-to-follow steps with illustrations and helpful charts. For first-time installers or those seeking a refresher, reviewing the initial pages will provide familiarity with the design and installation process. The guide includes graph paper, detailed illustrations of installation methods for sprinkler heads, pipe, and valve manifolds, and instructions on connecting the main line to the water supply or pump. Installation tips are provided throughout. A Glossary of Terms and Hunter Sprinkler Performance Charts are also included.

When developing the Liters Per Minute (l/min), Working Pressure, and Pipe Sizing charts, reasonable friction loss and acceptable water velocity for a residential irrigation system were considered. For any design or installation questions, consult your local Hunter distributor. For large residential or commercial projects, Hunter recommends contracting a professional irrigation designer. Contractors and designers can obtain additional information from their local Hunter distributor.

Table of Contents

• Plot Plan and Design
• Sprinkler System Design Capacity
• Service Line Size Chart
• System Design Capacity Chart
• Select Sprinkler Heads
• Locating Sprinkler Heads
• Divide Sprinklers Into Zones
• Area Capacity Example
• Locate Valves and Size Pipes
• Pipe Sizing Chart
• Point of Connection
• Sprinkler System Overview
• System Installation
• Making the Point of Connection
• Installing the Main Line
• Installing the Valve Manifolds
• Installing the Lateral Lines
• Installing the Controller
• Installing Heads
• Backfilling
• Materials List
• Glossary of Terms
• Watering Guidelines

1. Plot Plan and Design

A. Plot Plan And Design

The first step is to measure the property and indicate the house's location. Sketch your property on a separate piece of paper and add your measurements. Include all concrete/brick walks, patios, driveways, and fences. Note trees, shrubs, and lawns. Draw the plot plan to scale on graph paper (1:100 or 1:200). Note the scale and label lawn, shrub, ground cover, and large trees. Divide the property into areas (rectangles or squares), labeling them A, B, C, etc. Consider yard sections like front, back, and side yards, and shady areas.

Tools and Supplies You May Need: Permit, Electrical Tape, Hack Saw, Hammer, Pipe Wrenches, Plastic Sheet, Pliers, Rags, Rake, Screwdriver, Small Marker Flags, Shovels, Spray Marking Paint, Tape Measure, Trencher or Pipe-Puller Tunnel Kit or Hose Jetting Kit, Wire Cutters, Automatic Drain Valve, Insulated Wire Staples, Rain Shut-off Device, Shut-off Valves, Teflon Tape or Paste, Valve Boxes (150 mm and 250 mm), PVC Glue and Primer (if using PVC pipe), Pipe Clamps (if using Poly Pipe insert fittings).

2. Sprinkler System Design Capacity

B. Determine System Design Capacity

To plan an efficient system, determine the Sprinkler System Design Capacity – the available water for irrigation. For city water supply, follow steps 1-3. For lake, tank, bore hole, or well water, consult your pump installer for pressure and volume specifications.

1. Water Pressure (kPa) (Bars): Attach a pressure gauge to the outside tap nearest the water supply. Ensure no other water is flowing. Record the static water pressure in kPa or Bars.

2. Water Volume (l/min): Determine the water meter or water supply line size (usually stamped on the meter body: 15 mm, 20 mm, or 25 mm). If the supply connects directly to the city main, use the service line size. Measure the pipe's outside circumference and use the provided table to convert string length to pipe size.

3. System Design Capacity: Use the System Design Capacity Chart to find your Sprinkler System Design Capacity in liters per minute (l/min) based on water meter/service line size and static pressure. Record this and your system's working pressure (used for sprinkler head selection). Exceeding these maximums can lead to inefficient watering or water hammer.

SERVICE LINE SIZE TABLE: (Approximate String Length to Pipe Size)

SPRINKLER SYSTEM DESIGN CAPACITY CHART: (Static Pressure vs. Water Service Line Size vs. Max Flow Rate)

WORKING PRESSURE CHART: (Bars vs. kPa)

Note: Service lines are based on 30 meters of thick-walled PVC. Deduct 7.6 l/min for copper pipe and 19 l/min for new galvanized pipe. Working pressure is approximate at the head.

3. Select Sprinkler Heads

C. Select Sprinkler Heads

Three basic types of sprinklers for residential use: large area rotors, rotating stream spray sprinklers, and small area fan spray sprinklers. Do not mix large area rotors/rotating stream sprays with small area fan sprays on the same zone. Consider high-efficiency spray nozzles like Pro-Spray® MP Rotators®.

Sprinkler Spacing Guidelines:

• Large area rotors cover 8m x 8m or larger areas.
• Small area sprays are used in areas smaller than 8m x 8m.

Pop-up sprinklers are installed flush with the ground, while riser-mounted shrub heads are installed above ground. The 8m x 8m guideline is flexible; using larger rotors can mean less pipe, fewer valves, and a smaller controller.

EXAMPLE:

SYSTEM DESIGN CAPACITY: 49 L/MIN

WATER METER: 15 MM

SERVICE LINE: 25 MM

STATIC PRESSURE: 4.8 BARS, 480 KPA

WORKING PRESSURE: 3.5 BARS, 345 KPA

Sprinkler Types Illustrated:

• Pro-Spray® - Small Area Spray (3m to 5m spacing)
• PGJ - Mid-Range Rotor (5m to 11m spacing)
• Pro Spray® - MP Rotator® (from a 4' strip to a 30' radius)
• PGP® - Large Area Rotor (8m to 12m spacing)
• 1-20 - Large Area Rotor (8m to 12m spacing)

4. Locating Sprinkler Heads

D. Draw Sprinkler Locations

Decide where to install large area sprinklers (8m-12m apart) and small area sprays (3m-5m apart). Ensure overlap for even water distribution. Do not mix sprinkler types within a zone.

Placement Steps:

1. Step 1: Place sprinklers in the corners of the area. Draw their watering patterns using a compass.
2. Step 2: If corners don't overlap sufficiently (head-to-head spacing), place heads along perimeters. Draw their patterns.
3. Step 3: Check if perimeter heads cover the opposite side. If not, add full circle heads in the middle. Use perpendicular grid lines and compass arcs to ensure complete coverage.

Curved Areas: Convert curved areas to straight lines and place sprinklers as in rectangular areas. Adjustable arc nozzles are useful for curved areas.

TIP: Check with local agencies regarding permits, buried utility lines (gas, telephone), and required backflow preventer types.

5. Divide Sprinklers Into Zones

E. Divide Areas Into Zones

Most yards require zoning due to water capacity limitations. Dividing the yard into zones is a straightforward process.

Process:

1. Refer to the working pressure from page 2 for sprinkler spacing and l/min requirements.
2. Note each sprinkler's l/min next to it on the plan.
3. Sum the l/min for all sprinklers in an area and divide by the total system design capacity.
4. Round up the result to determine the number of zones needed for that area.
5. Divide sprinklers within the area so each zone has similar l/min, staying within design capacity. Avoid overloading zones.
6. Label zone valves (Zone 1, Zone 2, etc.).
7. Repeat for all areas.

AREA CAPACITY EXAMPLE:

(Example shows PGJ Mid-Range Rotors)

6. Locate Valves and Size Pipes

F. Locate Valves • Layout and Size Pipes

Each zone requires a valve. Indicate one control valve per zone and group them into a valve manifold. Place manifolds in accessible locations for maintenance, near the zones they serve, but away from direct spray when manually activated.

Lateral Line:

The two common pipe types are Polyvinyl Chloride (PVC) and Polyethylene (Poly). Consult your Hunter dealer for local recommendations.

1. Draw a line connecting all sprinklers in each zone, using the most direct route.
2. Draw a line from the sprinkler line to the zone valve.
3. Size the pipe starting from the head farthest from the valve. The pipe connecting the last two heads should be 20 mm.
4. Add the l/min requirements of heads to size the next pipe section.
5. Continue this process to the zone valve, ensuring no pipe is sized smaller than the chart indicates.
6. Repeat for each zone.

PIPE SIZING CHART (Maximum Flow Rates for Sprinkler Lines):

Connecting Sprinklers with PVC or Poly Pipe: Illustrations show correct and incorrect connection methods.

7. Point of Connection

G. Point Of Connection (P.O.C.)

Main Line:

1. Determine the system's point of connection near the water supply.
2. Draw a line connecting all manifolds and then to the P.O.C.
3. The main line should be one pipe size larger than the largest lateral line.

Connecting to City Water Supply: Use a brass compression tee to connect to the household water supply. Copper, PVC, or galvanized iron lines can be used. A backflow preventer is often required. Check local building codes or permitting agencies. Copper pipe may be required between the P.O.C. and the backflow preventer.

Connecting to City Water Supply in Freezing Climates: If the P.O.C. is in a basement in a freezing climate, install a drain valve after the isolation valve to drain the irrigation line before the first freeze.

Connecting to a Pump: For water sources like tanks, lakes, or wells, the system is pressurized by a pump. A foot valve can keep the pump primed. A check valve on the discharge line prevents backflow. A manual control valve regulates flow, and a pressure gauge monitors dynamic system pressure. Minimize elbows and bends in suction/discharge lines to reduce turbulence and friction.

Review Design: Ensure all areas have sprinklers, pipe layouts are correct, and pipe sizes are appropriate. The system is now ready for installation.

TIPS: Most professionals recommend PVC pipe for the constant pressure line. Some communities require copper. Check local ordinances.

System Overview Diagram

The diagram illustrates the components of a Hunter sprinkler system, including:

• Point of Connection (P.O.C.)
• Brass Gate Valve or Brass Ball Valve
• Valve Box
• Automatic Control Valve (PGV Series)
• Automatic Sprinkler Controller (X-Core Series)
• Smart Control Wireless Solar Sync Receiver/Transmitter
• Remote Control Roam Transmitter
• Sprinkler Controller Wire (Low Voltage)
• Waterproof Wire Connectors
• Cap for Future Use
• Male Adapters
• PVC (Polyvinyl Chloride) Pipe or Poly (Polyethylene) Pipe
• PVC Tee, Reducing Tee
• Poly Tee, Reducing Tee
• Swing Joint (SJ Series)
• Nozzles (MP Rotator® Series)
• Spray Sprinklers (Pro-Spray® PRS-40 Series)
• Sync 50 Automatic Pressure Regulator

8. System Installation

H. System Installation

Making the Point of Connection to City Water Supply:

1. Refer to the P.O.C. detail on page 7.
2. Turn off the water supply.
3. Dig a hole to expose the supply line.
4. Cut a 25 mm piece from the supply line, attach a compression tee, and tighten nuts.
5. Install the brass nipple and gate valve.
6. Install the valve box for access to the gate valve.
7. Turn the water back on.

Installing the Main Line:

1. Use marking spray paint to indicate pipe lines from the pump or P.O.C. to valve manifold locations.
2. On lawns, lay a plastic tarp alongside the trench (approx. 60 cm away).
3. Remove sod by cutting a 30 cm wide, 4-5 cm deep strip. Roll up sod and place on the tarp.
4. Trenching: Check local codes. If none exist, trench 25-30 cm deep. For lateral lines, trench 15-20 cm deep.
5. Installing Pipe Under Walkway/Driveway: Use the hammering method (cap ends of galvanized pipe and hammer through) or the jetting method (use a pipe-to-hose adapter and garden hose with a small stream nozzle to jet under concrete).
6. Install a backflow preventer if required by local codes.
7. Lay out pipe and fittings near trenches. Avoid getting dirt/debris in pipes.
8. Starting at the P.O.C. (or backflow preventer), measure, cut, and install pipe towards the last manifold or stub-out.
9. Backfilling the main line is discussed on page 12.

Installing the Valve Manifolds:

1. Refer to the valve manifold detail in the Sprinkler System Overview.
2. Maintain at least 15 cm clearance between valves for maintenance.
3. Provide a 8 cm or longer capped stub-out for future additions.
4. Install valve manifolds onto the main line.
5. Installing valve boxes is discussed on page 12.

Installing the Lateral Lines:

For phased installations or in landscaped areas, install one zone at a time.

1. Lay Out System: Use plot plan and flags to mark sprinkler and zone valve locations. Adjust as needed for coverage. Recheck l/min and pipe sizing charts if changes are made.
2. Mark lateral line locations with spray paint.
3. Trenching: Check local codes. If none exist, dig trenches 15-20 cm deep. A pipe puller may be used for poly pipe.
4. Install pipe and fittings, being careful not to get dirt/debris inside.
5. Backfilling lateral lines is discussed on page 12.

TIPS: Most professionals recommend PVC pipe for the constant pressure line. Check local ordinances regarding copper pipe requirements.

Assembling PVC/Poly Pipe: Illustrations show applying solvent to PVC pipe and fittings, inserting and wiping excess, and using clamps for poly pipe barb fittings.

Automatic Drain Valve Installation: Locate drain valves at low points in each zone for freezing climates.

9. Installing the Controller

Installing the Controller:

1. Choose a controller location. Most residential controllers should be indoors. Follow the manufacturer's installation instructions. A 220-240V or 115V electrical outlet is needed for the low voltage transformer.
2. Use color-coded irrigation wire to connect valves to the controller. You need one wire per valve plus one common wire. For a 5-zone system, use at least 6 wires total.
3. Installing Wire: Lay wire in the trench from the controller to valve manifolds. Protect wire by installing it directly beneath the pipe where possible. Leave expansion loops at direction changes to prevent stretching.
4. Connect wires to valves using waterproof connectors. One wire per valve plus one common wire connected to all valves.

Installing Heads:

1. Install all heads except the last one on a run. Leave the last one(s) off for flushing.
2. Flushing System: Manually turn on the zone valve. Flush out any dirt. Turn off the valve and install remaining heads when water runs clear.
3. Checking Coverage: Turn on the zone at the controller. Check that wire and connectors are working. Adjust sprinklers for proper coverage.

Backfilling:

1. Install valve boxes for easy access to valves before backfilling.
2. Ensure no rocks are directly next to the pipe. Backfill the trench in thirds, compacting the dirt. Allow for extra dirt when setting sprinkler heads and valve boxes.

TIPS: When deciding on the number of sprinkler wires, add at least two extra wires per manifold for future expansion. It's easier to install them now than later.

Metric to U.S. Conversions: 13 mm = 1/2", 20 mm = 3/4", 25 mm = 1", 32 mm = 1 1/4".

10. Materials List

Use the plot plan and check lists to create a materials list. Consult the Sprinkler System Overview for part names. Mark the plan and list items as you count or measure.

1. Point of Connection: List materials by size. Check backflow prevention requirements.

2. Pipe and Fittings: Measure and list pipe by size. Add extra pipe for waste. Count and list fittings by size and type.

Point of Connection Details:

• Non-Freezing: Valve Box, Water Meter, Point of Connection (P.O.C.), Brass Gate Valve or Brass Ball Valve, Male Adapter, Brass Compression Tee.
• Freezing Climates: Brass Gate Valve or Brass Ball Valve, Point of Connection (P.O.C.), Brass Compression Tee, Water Meter.

PVC Pipe and Fittings: (Main/Lateral, Tee, Elbow, Reducer Bushing, Reducing Tee, Male Adapters, Coupling)

Polyethylene Pipe and Fittings: (Main/Lateral, Tee, Elbow, Reducer Coupling, Reducing Tee, Male Adapters, Coupling)

3. Valves: Count valves by size and list materials needed (PGV Valve, Valve Box, Male Adapters, Waterproof Wire Connectors).

4. Controller: Determine controller size based on the number of valves. Measure wire run from controller to farthest valve. Use color-coded, multi-conductor low voltage wire (one wire per valve + common wire). Example calculation provided for wire length.

5. Sprinklers: Count sprinkler heads by type and record totals.

• Gear Drive Rotors – Pop-Up and Shrub: PGJ (13mm inlet), PGP® (20mm inlet), 1-20 (20mm inlet).
• Spray Sprinklers with Adjustable Arc Nozzles: Pro-Spray® (13mm inlet), PS Ultra (13mm inlet), Pro-Spray (1/2" inlet).

6. Hunter Swing Joints, Pre-assembled (SJ Series): List sizes and quantities.

7. Swing Joint Assemblies: Determine parts needed based on sprinkler type (e.g., 1/2" Inlet Sprinkler requires 1/2" Marlex Street Ell, 1/2" x 8" nipple).

TIPS: Never drop PVC pipe. Handle with care to avoid cracks that can lead to bursting.

11. Glossary of Terms

Definitions for terms used in sprinkler system design and installation:

• ARC: Sprinkler rotation or spray pattern degree.
• BACKFLOW PREVENTER: Device preventing contaminated water backflow into drinking water supply.
• CHECK VALVE: Allows water flow in one direction; prevents backflow.
• CONTROLLER (TIMER): Determines when and how long valves operate.
• FLOW: Volume of water moving through a pipe or sprinkler (l/min or m³/hr).
• FRICTION LOSS: Drag or friction from water flow, increasing with velocity.
• HEAD-TO-HEAD: Sprinkler placement ensuring overlap for complete coverage.
• LATERAL (Lateral Line): Pipe from valve to sprinklers.
• LOW HEAD DRAINAGE: Water flowing out of low elevation sprinklers after valve closure.
• L/MIN (Liters Per Minute): Available water volume for system design.
• MAIN (MAIN LINE): Pressurized pipe from P.O.C. to zone control valves.
• MANIFOLD: Group of valves.
• P.O.C. (POINT OF CONNECTION): Sprinkler main line tie-in point.
• POLY PIPE: Flexible polyethylene pipe, often used with insert fittings and clamps.
• PRECIPITATION RATE: Rate of water application (mm/hr). Matched precipitation ensures even watering.
• PRESSURE: Measured in kPa or Bars (Static or Dynamic).
• PROGRAM: Timer settings for watering days, start times, and duration.
• PVC PIPE: Rigid pipe, commonly used in warmer climates, requires solvent and primer.
• RADIUS: Distance water sprays from the sprinkler.
• ROTORS: Gear-driven sprinklers with a solid stream, covering larger areas.
• SPRAY HEADS: Sprinklers emitting a fan-type spray of small droplets, covering shorter distances.
• STATION: Controller connection point for a valve.
• TIMER: See Controller.
• TRENCH: Trenches for lateral lines should be 15-20 cm deep. Main lines are deeper. Install low-voltage wires below main line pipes.
• VALVE: Controls water flow; typically automatic control valves in sprinkler systems.
• SPRINKLER ZONE CONTROL VALVES: Manual or automatic valves.
• VOLUME: Amount of water available or used (liters or m³).
• WATER HAMMER: Pressure surge from sudden valve closure, causing vibration or noise.
• WIRE: Low voltage, direct burial wire connects valves to the controller.
• ZONE: Area watered by one sprinkler valve.

12. Watering Guidelines

Application Rates: Watering needs vary by plant type, soil, and climate. New lawns need frequent moisture; established plants need less frequent watering.

Watering Guidelines:

• Operate only one valve at a time.
• Water early in the morning when wind and pressure are optimal to reduce evaporation. Avoid early evening watering to prevent diseases. Watering during hot summer days may burn plants due to salt residue.
• Lawns typically require 40-50 mm of water per week in hot months; hot, arid areas may need more.
• Manually activate the system weekly to check operation and clean sprinklers.

Freezing Areas: In freezing climates, turn off the controller, close the main shut-off valve, drain the system, and blow out remaining water before the first freeze. Consult your local Hunter dealer if unsure.

Choosing Sprinkler Nozzles: Ensure even precipitation over each zone by selecting appropriate nozzles or zoning sprinklers with similar precipitation rates. Consider flow rate and arc of coverage. Matched precipitation means sprinklers apply water evenly.

Watering Schedule Examples:

• Cool, non-arid climates: Apply 25 mm of water per week.
• Hot, arid climates: Apply 50 mm of water per week.

Soil Type Adjustments:

• Clay soils: Program shorter run times, more start cycles per day, fewer watering days per week.
• Loam soils: Program longer run times, fewer start cycles per week.
• Sandy soils: Program shorter run times, more start cycles per day, more watering days per week.

SPRINKLER RUN TIME SCHEDULE – OVER 7 DAYS: (Table showing minutes for Spray Sprinklers, PGJ Rotors, PGP® Rotors, 1-20 Rotors for 25 mm and 50 mm water application per week).

Note: For complete product information and performance charts, see the Hunter Product Catalog or visit www.hunterindustries.com.

Sprinkler Flow Example: 90° = 5 l/min, 180° = 10 l/min, 360° = 20 l/min.