Irrigation Controllers / Timers: How To Select – Install – Replace and More

Posted on September 12, 2009 by SprinklerWarehouse

Irrigation controllers are essential components of a lawn sprinkler system.

What is an Irrigation Controller?

Irrigation controllers, also known as irrigation timers or lawn sprinkler system timers, are the nerve centers or brains of the sprinkler system. Sprinkler system timers send electric signals to the irrigation valves. The valves regulate the flow of water to the sprinkler system.

Lawn sprinkler system timers are the devices that allow you to set a watering schedule to meet your needs. You can set the days you want to water, the time of day you want the sprinklers to come on, and how long you want them to apply water.

Sprinkler system controllers may be mechanical, partly automatic, or fully automatic. Although lawn sprinkler system timers are largely maintenance-free, the home or property owner might wish to upgrade and replace irrigation controllers or install irrigation controller parts or extra features. Sprinkler timer installation or replacement is very straightforward and easy and can be done by either the homeowner or by an irrigation professional.

How to Choose an Irrigation Controller / Timer

The only important decisions you need to make when selecting a controller / timer are as follows:

  1. Controller mounting location: indoor or outdoor
  2. Number of stations or zones – must be at least as many zones or areas your sprinkler system is broken up into.
  3. Number of programs (1, 2, 3, or 4) – should have at least 2 or more programs to give you the watering flexibility you want or need. The programs on a controller are very different from the number of stations on a controller. This is explained below.

IMPORTANT: The rest of the features you can choose from on a controller are just for added benefits or increased flexibility.

Indoor vs. Outdoor models
Sprinkler system controllers come in a wide range of makes and models. Choose lawn sprinkler system timers depending on the size of the sprinkler system and the user’s needs. Lawn sprinkler system timers come in two different types: indoor models and outdoor models. Indoor sprinkler system timers need to be sheltered from weather, and can be conveniently plugged directly into a 110-volt outlet. This is because they come with an external transformer as part of the plug-in cord that converts the 110-volts to 18 volts. Typical locations for mounting indoor timers are in the garage, building, covered patio, shed, pump house, closet, etc. Outdoor lawn sprinkler system timers are convenient, weather resistant, durable, and typically need to be hard wired for power instead of plugged into a 110-volt outlet. This is because the transformer is located inside the protective weather resistant cabinet and it is assumed that the electrical connection will need to be weather resistant also.

Outdoor controllers can be used as indoor controllers just by adding a pig tail (3 prong plug and power cord) to the power wires of the timer. People do this all the time to be able to get all the benefits of an outdoor timer with a weather resistant cabinet and typically all kinds of added features. An example of this is the Hunter ICC model controller which is one of Hunter’s best controllers. It has so many nice features that people will just add a pig-tail and make it an indoor timer.

Controller Stations
Typically, residential systems use irrigation controllers with 2 to 9 stations, while systems for commercial or public properties can have 32 – 48 stations or more. Each station regulates one zone or area of the lawn sprinkler system. When selecting irrigation controllers, know how many stations the system needs. Choose a sprinkler timer with extra stations, in case of later expansion.

Controller Programs
The number of programs a controller or timer typically has can range from 1 up to as many as 4. They are usually labeled as Program A, B, C, and D. Some controllers only have 1 program while most have at least 2 or more. A program is a set of watering instructions for stations that will run on the same days. When you set up Program A on the controller, you are setting the days you want to water, the time of day you want to start watering, and how long you want to water. If you have a controller with two programs, the lawn areas can be set up to be watered every day on one program and the flowerbeds and shrubs every other day on the second program. When a controller starts a program, it will go through the entire program before stopping or repeating the program.

Types of Controllers – Mechanical or Solid-State (Digital)

Some irrigation controllers are fully digital, including easy touch screen features. Digital sprinkler system controllers with basic features are suited to a more conservative budget. Other lawn sprinkler system controllers have an array of features and options for convenience and ease of operation.

Mechanical sprinkler system timers use manually-operated sliders and switches for programming. An electromechanical controller uses both an electric clock and mechanical switching. That is to say, they are made of a motor, wheels, dials, gears, and pins. These controllers are typically, easy to understand how to operate and program, and are less susceptible to power spikes and surges, but are much more limited in features than solid-state digital irrigation controllers.

Solid-State controllers have digital readout screen, have no moving parts, and use integrated circuits for the clock, memory and control features. These controllers are adaptable, offering many more features at a reasonable cost. More advanced Solid-State controllers such as Smart Controllers can adjust the watering schedule automatically throughout the year. Still other controllers operate solely on battery power, for areas with limited or no electricity. Solar-powered controllers are also available.

Features Available on a Controller

Some controllers come fully loaded with features for efficiency and convenience of operation. In others, extra features may be optional. Key features available on a controller can include:

*Clock and calendar settings

The user can program watering times, control watering cycles, and make seasonal adjustments.

*Manual start and manual station operation

The user can operate the stations or start the automatic cycle without affecting the programmed start time. This is helpful when you need to do some maintenance to your system. This feature makes it easier to check for leaks, misaligned or broken sprinkler heads and even perform basic tune-ups steps such as adjust spray patters and replace nozzles.

*Master Switch

The master switch overrides the automatic functions of the stations.

*Master Valve Control

The master valve prevents flow to the system, in case of water problems or system failure.

*Station Omission

The user chooses which stations operate, and which do not.

*Pump Start Lead

This turns on a pump start relay whenever a station activates, to combine irrigation and pump control. A Pump Start Relay is an electronic device that uses a signal current from the irrigation controller to activate a pump to provide water to the irrigation system. Never connect the controller directly to a pump as damage to the controller will result.

*Rain Sensor

A rain sensor shuts down the irrigation system if it detects rain. The purpose of a rain sensor is to stop watering when precipitation is sufficient. Most controllers allow for a sensor to be connected directly to the controller and allow you to easily override the sensor by using a Rain Sensor Bypass switch on the controller.

*Battery backup

The controller reverts to battery power in case of power interruption or outage.
The battery typically will just allow the timer to maintain the time, date, and watering schedule. On some controllers it allows the user to program the controller without AC power. IMPORTANT: watering will not occur without AC power. The battery only keeps the time, date, and watering schedule in memory until the AC power is restored or the battery dies.

*Non-Volatile Memory

The controller retains its program data without a battery, even if the power fails.
The non-volatile memory allows the timer to maintain the time, date, and watering schedule indefinitely. IMPORTANT: watering will not occur without AC power.

*Delay

The delay feature allows time for valves to close fully in one zone, before opening the valves in another zone.

Tools Needed to Install Irrigation Controller / Timers

1. 3/8″ electric drill, cordless or with cord

2. Masonry bit, if drilling holes in stucco.

3. Metal center punch. If drilling into wood, the punch isn’t necessary.

4. Wood type drill bit – to drill holes through the timer cabinet
5. Black sharpie or felt-tipped marker
6. A hammer
7. A level
8. Screws, with matching plastic wall anchors
9. Screwdriver

How to Install, Wire, and Set Up a New Irrigation Controller

1. Decide on the location for the sprinkler controller. Consider factors such as power supply, whether the sprinkler timer is an indoor or outdoor model, whether it will plug into an outlet or needs to be hard wired. Also consider convenience of operation, and ease of access for the user.

2. Unpack the timer. Some hardware and supporting documents will be included for the installation.

3. Remove the clock/timer face from the controller. The face should snap out easily. Look for clips or plastic tabs along the front or sides of the unit. Also detach the ribbon connector. If desired, remove the cabinet door by taking out the steel pin connecting the door to the main cabinet.

4. For extra stability, drill extra mounting holes through the back of the cabinet. Irrigation controllers usually come with pre-drilled holes or mounting hardware in the back, so this step is optional.

5. If hard wiring the timer, cut electric power. Turn off the breaker to the wires. Double check the wires to be sure the electricity is off, by using a volt-meter or ticker. The volt-meter gives off an alarm if it detects electricity in a line. An active electrical current can cause injury to the user, or throw off sparks that can damage the irrigation controller.

6. Mount the cabinet at a comfortable height, usually about eye level. Place the cabinet against the wall, and use the level to check that it is even. Use the felt tipped pen to mark the wall through the holes in the back of the cabinet.

7. If drilling into stucco, use the metal center punch. Line the punch up to the marks on the wall, and give it a firm whack with the hammer to make a small indentation in each mark. This keeps the stucco drill bit centered and stable. Drill holes into the wall at the marks.

8. Put the plastic inserts into holes. Tap them flush against the wall with the hammer.

9. Using screws, mount the timer cabinet to the wall. Connect the station wires. Make notes of which wires are responsible for each zone or valve of the sprinkler system, to avoid guesswork in the future.

10. Re-mount the timer face and re-attach the ribbon connector to the board. Do not turn on the power until these steps are complete. Replace the cabinet door. The controller is now ready for programming and operation.

Wiring the Controller to the Valves

Purchase sprinkler or irrigation wire. Buy one strand more than the number of zones desired. Usually, the white wire is the common wire, and the others will lead to individual sprinkler valves.

Turn off the power to the controller. Be sure to follow the manufacturer’s instructions when attaching wires. Look for a terminal on the controller that says “C”. Attach the white or common wire.

Run a wire from the solenoid on each zone valve back to the controller. If the valves are underground, the wire will run alongside the PVC pipe leading to the valve. Be sure the connections are waterproof. Water leakage will damage the solenoid.

Each wire will regulate a different zone from a station on the controller terminal. Delegate the stations as desired and attach the individual wires. Make a written plan or diagram of the setup, to avoid confusion in the future. One can also mark the wires as Zone 1, Zone 2, and so on.

Do not turn on the power until wiring is complete.

How to Replace an Existing Irrigation Controller:

If you already have a controller that is giving you problems and find that you need to replace it with a new one, let me reassure you that it is very easy to replace a controller and most any homeowner or irrigation repair person can handle this task. First, if possible, it makes your job easier if you can write down all of your existing programming from the old controller. Specifically, you want to write down the specific days scheduled for watering, the start times and how long each zone is scheduled to be watered. You will need to use this information to program the new controller. If the old controller is completely dead and you can not get this information, no worries, as you can program the new controller to water a few days a week and the rotor zones for 20 minutes and the spray head zones for 5 to 8 minutes each time they come on. A good start time is 4:00 or 5:00 am so that all the watering is completed before you need to start using water in the house in the morning. Then you can adjust these settings later as you find that the yard is getting watered too much or not enough.

Make sure to unplug your transformer from the wall, if you have an indoor system, or turn off the power to the timer at the breaker box, if you have an outdoor system. Use that volt-meter to verify the power is not reaching the controller. The next step is to label each of the control valve (hot) wires on the old timer. Label them according to the zone they are connected to, zone 1, zone 2, zone 3, etc.  Also label the common wire connected to the common connection and the pump start wire if you are using a pump. Now you are ready to disconnect the wires.

If possible, buy the same model and brand as the controller that was already in the system. If you can not buy the same model, that’s ok, just get one that has the correct number of stations or zones that you had on your old timer and make sure you get all the features you want. Now is a good time to upgrade to a better more feature rich timer. Take the old controller out and mount the new one on the wall. Reconnect your wires as they are labeled and reprogram your controller with your watering schedule. Turn the controller on and make sure all zones are working properly.

I told you, replacing a controller is very easy as long as you label the wires before removing them from the old timer.

Differences in installing an indoor controller and an outdoor controller

Sprinkler system controllers come in interior or exterior models. Indoor sprinkler system timers plug easily into an electric outlet. The interior models have a power supply or transformer that converts 110/120 volts of standard house power to the 18-24 volts required for sprinkler system operation. Exterior sprinkler system controllers are housed in sealed weather-resistant cabinets. The exterior controller has a transformer inside the cabinet, and must be hard wired into the power supply.

Indoor irrigation controllers can also be installed outside. Weather-resistant cabinets are available separately, to convert indoor controllers to outdoor use.

How to install a controller when a pump is also going to be used

A pump brings water from a well, pond or nearby water source to the sprinkler system. When using a pump instead of a municipal water supply line, choose a sprinkler timer that will work best with the pump.

Electric sprinkler system controllers can turn the pump on and off at pre-programmed times. Most irrigation controllers have a pump circuit built in. The timer uses a voltage relay to start and stop the pump. The relay allows the controller, which operates on 18-24 volts, to communicate with the pump, which uses standard house voltage (110/120v).

Do not connect the irrigation controller to an existing relay. If the pump already has a starter circuit with relay, the user will need to install a new one for the controller.

To hook up the pump, connect the wires from the pump start switch to the pump start terminal(s) on the controller. Some irrigation controllers feature zone-by-zone programming for more effective pump operation.

Use a flow switch with the sprinkler timer relay. The flow switch turns off the pump if there is no water flow, preventing the pump from overheating in case of a system malfunction or water supply interruption.

A delay feature is helpful when installing an irrigation controller with pump. The delay allows slow-closing valves to shut down completely in one zone, before the next zone starts operating.

Check with local authorities to be sure of bylaws and water codes. Some areas have regulations regarding the operation of pumps and lawn sprinkler systems.

Items to Consider Adding to The Controller

*extra stations

Many lawn sprinkler system timers can be adapted to add extra stations, in case of expansion or amendments to the lawn sprinkler system.

* remote control

Remote control allows the user to operate indoor or outdoor sprinkler system controllers from a distance.

*computer control

The user can control the sprinkler timer and features from a computer.

*weather devices

Some irrigation controllers have built-in rain sensors. If not, adding a rain sensor or other weather device to the controller is a practical option for most home and property owners. Weather devices also sense outdoor temperature to guard against freezing. A solar power converter is a handy add-on feature available in some sprinkler system controllers.

*mounting pedestal

Instead of mounting the sprinkler timer to the wall, the user has the option of mounting the controller on a stand-alone pedestal. Some irrigation controller pedestals include a separate wiring board.

Remote Control

If the system doesn’t come with a remote, the user can add a remote control transmitter & receiver to most lawn sprinkler system controllers. The remote control comes in handy if the user wants to do work or maintenance on the sprinkler system, or operate the controller from a remote location. It makes spring check ups and maintenance much easier. You can turn zones on and off without walking back and forth to the timer.

Rain shut off devices or other weather devices

Rain sensors and rain shut-off devices automatically adjust the system’s function when rain is detected. Some sprinkler system controllers feature seasonal adjustment options. Other weather devices include wind sensors, which shut down the system in case of high winds, or temperature-sensitive features to regulate the function of the lawn sprinkler system.

Where to Buy a Controller / Timer

For more information about irrigation controllers, options and features, or to purchase a new irrigation controller or sprinkler timer, go to www.SprinklerWarehouse.com.

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Irrigation Valves – A Look at All the Parts of a Valve

Posted on August 30, 2009 by SprinklerWarehouse

All The Parts of an Irrigation / Lawn Sprinkler Valve

The main components of sprinkler valves are the diaphragm, solenoid, springs, and various gaskets or O-rings. The solenoid, an electric cylinder, is a crucial part of an automatic valve. The solenoid receives electric messages from the sprinkler system controller, and in turn controls the movement of the diaphragm. Manual irrigation valves don’t require a solenoid.

The diaphragm is the rubber plug inside the valve, responsible for opening or shutting off the flow of water. Behind the diaphragm is a wire spring.

Some irrigation valves have a jar-top lid; in others, the lid may be held in place with screws. Many valve designs feature a bleed screw, which can be tightened or loosened to manually control the flow of water to the valve.

If one of the lawn sprinkler valves needs repair, it’s usually not necessary to replace the entire valve. The valve can be disassembled, and the components separately replaced. Major manufactures of sprinkler valves also make replacement parts, and it’s often easier to replace the parts than to cut the entire valve from the pipe

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Irrigation Valves – A Review of All The Types and When and How They are Used

Posted on August 30, 2009 by SprinklerWarehouse

Irrigation / Lawn Sprinkler System Valves – What Are They

Irrigation valves or lawn sprinkler valves are an essential component of lawn sprinkler systems. They control the flow of water in lawn sprinkler systems. Sprinkler system valves come in a variety of models, including below ground inline valves and above ground anti-siphon valves.

Available in solid brass or durable plastic, sprinkler valves operate from a manifold above or below ground to regulate water flow to the lawn sprinklers.

Lawn sprinkler systems may be manual or automatic. Automatic lawn sprinkler systems consist of the controller / timer, the sprinkler valves, the pipes, and the lawn sprinklers. Each valve controls a different zone, or area, of the lawn sprinkler system. The controller sends electric low voltage (24 volt AC) signals to the valves, telling them to open or close.

Sprinkler valves come in many different styles. Globe or angle irrigation valves work with a separate backflow preventer, and anti-siphon valves have the backflow preventer built-in. Rain Bird valves, Toro valves, Hunter valves, Irritrol valves and Weathermatic valves are all reliable, well-known products that, with proper maintenance, will last for many years.

Irrigation Valves – Types of Valves and What They Are Used For

Shut-off Valves

Emergency shut-off valves stop the flow of water to the irrigation system. If repairs are needed to the sprinkler system valves or any other part of the irrigation system, the shut-off valve prevents the need to turn off the entire water system to the house or what ever else the water feeds.

Emergency shut off valve: You should install this sprinkler system valve as close to the water source as possible and should be the same size as the pipe you are installing it on. If you do not install this valve, you will have to shut the water off to the entire house when you want to make repairs or work on the irrigation line. You only need to install one of these shut off valves for your irrigation system and it will either be installed under ground in a valve box or in the basement depending on where your water supply connection is located.

If you are using a water meter from the city as your source of water, it is best to tee off the pipe coming out of the water meter (the one headed to feed the house) as close to the meter as possible and use the tee to start the water supply to the sprinkler system. In this case, you would install the shut off valve close to the tee on the line headed to feed the sprinkler system. Some people will put the tee close to the meter but then install the shut off valve just before the backflow device which may be installed on the side of the house. If you are in an area that freezes and you will be using the basement water supply piping as your sprinkler system water supply, install the shut off valve in the basement on the piping before the backflow device.

The most popular valves used for this purpose are the gate valve, ball valve, disc valve or butterfly valve. The gate valves are the most inexpensive and tend to NOT Close completely plus they are typically metal and corrode quickly making it difficult if not impossible to use. Your best bet is to use a PVC ball valve (highly recommended) since they are a more reliable choice. They close completely and they do not corrode or rust which means you should always be able to open and close them easily even when buried under ground in a valve box.

Control Valves (as known as Zone Valves)

Irrigation control valves are used to turn the irrigation system on and off and there are two different types to choose from:
1.) Globe and Angle Valves
2.) Anti-Siphon Valves

The globe and angle valves come in any size and are usually installed under the ground or in a vault or valve box. Since there is not a backflow preventer attached as part of the valve, you will need to add that separately. This is the most common type used in sprinkler systems. However, you may choose to use the anti-siphon valve, which comes only in 3/4- and 1-inch sizes and comes complete with a backflow preventer. The anti-siphon valve absolutely must be installed above the ground and must also be 6 inches higher than that of the highest sprinkler head.

Valves come in brass and plastic; the most common ones used today are the plastic ones. The brass valves will ultimately last longer if installed in the sunlight. Both types are reliable for an automatic system, but for manual systems the manual brass valve is the best choice because it lasts much longer. Valves today are fairly maintenance free.

As for pressure losses and valve size, the automatic valves should be sized based on the manufacturer’s flow range chart and will not necessarily be the same size as the pipe. However, it is more common that it will be the same size as the pipe it is installed on. A manual valve is much more adaptable than the automatic and you do not have to depend on electricity to power it, rather it is done manually, hence the name. A manual irrigation control valve needs to be either an angle or globe type with replaceable rubber seals and not the gate type as the gate valve is not made to be opened and closed regularly.

Above Ground Anti-Siphon Valves

Anti-siphon valves have a built-in backflow preventer to keep irrigation water from washing back into the household’s main water supply. Use Anti-Siphon valves in locations where the use of a pressure vacuum breaker (PVB) or double check valve is not required by city codes. Some areas of the country, such as in California and Arizona, require backflow prevention for every zone. Check your local city codes to determine what type of valves are required. The Anti-Siphon valve is a combination valve that has an atmospheric vacuum breaker and an electronic control valve all in one unit. It provides backflow prevention on every zone, saving costs by eliminating the need for a separate backflow preventer. Anti-Siphon valves are installed above ground and will prevent back flow if properly installed. Anti-Siphon valves should always be installed at least 6” above the highest head on the valve line, and should never have another valve installed further down the line from the main valve

Below Ground Inline Valves

These valves are often globe valves or angle valves. Inline valves are installed underground, protected by a valve box. Below ground inline valves require a separate backflow preventer, installed to meet local bylaws and regulations. However, the great thing about inline valves is that they are typically less expensive than anti-siphon valves and you can install them in the middle of each zone (or section) of your sprinkler system which keeps the pressure loss in the zone more balanced and uniform. Furthermore, you save money on pipe since you end up with one mainline traveling through your yard supplying all you valves instead of having multiple runs of pipe in the same trench heading from the anti-siphon valve manifold to each zone. Plus you only need one backflow preventer device protecting the whole sprinkler system instead of paying for one on each anti-siphon valve. Using a single backflow device with inline valves is a better way of installing your system and it will last longer than the anti-siphon valve plastic backflow device which relies on gravity and has no other parts to assure it functions properly. One other important note: anti-siphon valve back flow vales can not be tested to see if the backflow prevention is functioning, however, backflow devices purchased separately to be used with inline valves can be tested to assure they are functioning correctly. Using inline valves is a more professional way of installing your sprinkler system.

Globe Valves

Globe valves once had a spherical body, but modern globe valves have changed in shape, and only the name remains. Water flows through the valve without changing direction. The two halves of the valve body are separated by an internal baffle. A movable plug, or disc, screws in to shut off the valve. In manual globe valves, the plug connects to a stem which operates by hand wheel. In automatic globe valves, the stem is smooth.

Angle Valves

Named for their angular design, angle valves direct the flow of water at a right angle to the valve. Water flows into the valve, then changes direction 90%.

The Valve Manifold

The manifold is a group of control valves attached to a pipe. Water enters the manifold from the main water supply line. The water is then routed through the control valves. The valve manifold may be below or above ground.

To build the valve manifold, use a length of PVC pipe. Space the valves about three to six inches apart. The number of valves determines the overall length of the manifold pipe. Include an extra connection or two, for possible expansion to the system later. Save time and work by purchasing a ready-to-install manifold kit, which includes the sprinkler valves and all necessary parts and instructions. Many manifold kits have a flow control feature, to help conserve water.

Valve Boxes

A valve box is a plastic cover that protects the valves and wiring from damage and debris. Above ground, the valve box also protects the valves and manifold piping from harsh sunlight and inclement weather, or damage by accident, animals or vandalism.

Backflow Prevention Devices

Backflow prevention devices will prevent irrigation water from lawn sprinkler systems from backing up into the drinking water. Irrigation water may contain contaminants such as pesticides and other chemicals, as well as waste products and dirt. While these elements don’t harm the lawn, they create health risks in public or household drinking water.

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Should You Buy a Solenoid Replacement or Buy a New Valve and Replace the Top of the Valve?

Posted on August 25, 2009 by SprinklerWarehouse

It is better to buy the valve and take the top off the new valve and replace the old valve top. Plus a new valve is cheaper than if you buy the parts separately. This way you will end up with a new diaphragm, solenoid, and internal filters. You will have a new valve since the bottom body piece is only a PVC base and does not go bad. The trick is you must use the exact model valve as the old valve. If you can not find the same valve (if yours is so old that we do not have it online) then we suggest you replace the entire valve.

I hope this helps…..

Steve Okelberry

Filed under: Irrigation Repair | Tagged: , , | 2 Comments »

What are the Best Sprinkler Heads? Who Manufactures the BEST?

Posted on August 25, 2009 by SprinklerWarehouse

Both Hunter and Rain Bird make very good rotors and spray heads.

If you go with Hunter, make sure you use the Pros series or the Institutional series sprays for areas under 15 feet radius, and as far as their rotor models You can not go wrong with the PGP series, or I-20 series rotors.

If you go with Rain Bird, make sure you use 1800 series sprays for smaller areas (less than 15 feet radius) and as far as their rotor models You can not go wrong with the Rain Bird 5000 series or the 5000 Plus Series Rotors.

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How to Install a Sprinkler System

Posted on August 25, 2009 by SprinklerWarehouse

"Here are some of the things you need to know to do it right".

A well designed, properly installed lawn sprinkler system makes it easy to water your home landscape and adds value to your property. On the other hand, a poorly designed, improperly installed system is inefficient, wastes water, can damage brick, siding, and fencing, and can be a maintenance nightmare. Here are some of the things you need to know to do it right.

First and foremost, the system needs to be designed properly:
It is nearly impossible to get good results if the system isn’t designed right from the beginning. You need to know how much water pressure and flow you have available. There is no rule of thumb. If you have a large water meter and a small property, you may be able to divide your property up into three or four zones and have adequate flow and pressure to make the system work. On the other hand, with a large lot and a small well, you might need 15 or 20 zones.

If you are on a well, do your "Home Work"
as there can be issues with the pump cycling on and off, water quality, etc. Zones that are sized too small or large can damage your pump. You may also need a sand separator or filter installed to prevent valves and sprinkler heads from becoming fouled.
Visit
www.SprinklerWarehouse.com’s Sprinkler School for detailed info on using
pumps with your irrigation / lawn sprinkler system.

If you are on a city water meter, first check your local codes about the
use of a backflow device to protect the drinking water.
Most cities require some type of backflow prevention device and the requirements vary. Many areas allow a double check valve assembly (DCA), which in some places may be installed below ground in a box, while others will only allow a pressure vacuum breaker (PVB), which must be installed above ground and protected from freezing. Other areas only allow a reduced pressure principle device (RPZ), which also must be installed above ground. In some cases, atmospheric vacuum breakers (AVB) may be used, but these must be installed on each zone after the valve, with no additional valves downstream and may not be subject to continuous pressure. If the proper backflow prevention device is not used, there is a risk of contamination to the public drinking water supply. In
some cases you will be required to get a permit, have your system inspected, and have the backflow device tested for proper operation. Many cities and some states also now require that a rain sensor be installed on new systems. This device shuts the system off automatically when it rains.
A rain shut off device will pay for itself very quickly in saved water.

Next, you need to know the static water pressure in your water main.

You can measure this by connecting a pressure gauge to a hose adapter and attaching it to a hose bib on the outside of your house. Make sure no water is being used inside the house and then turn on the faucet. The gauge will read the current pressure inside the city water main. You might want to take several readings as the pressure can vary throughout the day. In many cities the pressure varies throughout the city depending on the time of day and the demand for water.

Spray Heads and Rotor Heads:
The design pressure is the pressure required at the sprinkler nozzle for it to perform properly.
Spray heads work best at about 25-30 psi, while rotors work better at 40-50 psi. It is important that there be sufficient flow and pressure to the nozzles so that they provide proper coverage. Otherwise there will be dry spots in the lawn. It is also important to match the precipitation rates of the nozzles. Most spray heads already have matched precipitation rates for the various nozzles within a manufacturer’s product line, but with rotors, it is important that the proper nozzles be selected.
(Each rotor you buy from
www.SprinklerWarehouse.com will come with a full set of standard nozzles). If you use the same size nozzle for different rotors that are watering a quarter circle, a half circle, and a full circle, then some areas will be overwatered, while others
under watered. The full circle rotor is covering four times the area of the quarter circle, so it needs to have a nozzle that is putting out four times as much water. It is also important to group plants that have similar watering requirements together in a zone and water them at the same time.

To get the proper size zone, one must know the flow capacity of the meter.

For example, a typical one inch meter can provide a flow of about 25 gallons per minute with a pressure loss of 4.0 psi. Take the static pressure and allow some safety margin (many recommend 10%). So for a static pressure of 50 psi, you might consider a working pressure of 45 psi, then calculate the friction loss through the supply line from the city water main (usually a copper line), the meter itself, the backflow prevention device, the pipelines, the valves, pressure regulators (if used), and finally arrive at the design pressure. If there is not sufficient pressure, then a person might need to make the zones smaller or increase the flow and pressure by having a larger meter installed. Needless to say, there are a lot of factors to consider when designing a system.
This issue is important so let’s go into it with a little more detail to help
you out.

You will need to base your design on the gallon per minute (gpm) flow and the
pressure you have available. The available flow will dictate the max gpm size of
your zones our sections, and the available pressure will dictate the size of
pipe and the types of sprinkler heads you will be able to use (sprays or
rotors).
There are 3 rules you must follow when determining your flow and working
pressure:
1. Do not go beyond 75% of the maximum safe capacity for the water meter.
2. Do not exceed 10% of the static water pressure as a pressure drop through the
water meter.
3. Do not go beyond velocities of 5 to 6 feet per second in the service line
which feeds the water meter from the city main.

To calculate the exact maximum flow through your water meter you should refer
to Chapter 10 in the book Simplified Irrigation Design or you can determine
available pressure and flow from the flowing link at

www.SprinklerWarehouse.com’s Sprinkler School

There are entire books written on the subject of hydraulics and proper design. Even if you decide you want to install your system yourself, consider
reading one of the books offered at

www.SprinklerWarehouse.com Book Store or thoroughly read through the

www.SprinklerWarehouse.com’s Sprinkler School section..

Buy the best parts you can afford.
Do not skimp. Professional grade materials last longer and require less maintenance. Especially do not buy the cheap do-it-yourself sprinkler timers they sell at the big box stores. You will be using your controller regularly, so buy a sturdy, easy-to-program controller like the pros use. You won’t regret it.
www.SprinklerWarehouse.com sells
nothing but professional grade sprinkler parts and supplies. We ship extremely
fast and we offer you the lowest prices on the web…. We want you business
and we plan to earn it!

Call to get the utilities located and marked.
With a proper design in hand and several boxes full of parts, you are now ready to install. But wait, first call to get the utilities located. In most states, you must call before you dig. In many areas you can call 8-1-1 and have most of the utilities located free of charge. You must usually call at least two working days before you can commence digging. Gas, water, and sewer lines are usually not located past your property line, so you may need to locate these yourself. Be careful, although breaking a water line can be a big nuisance, cutting a gas line with a shovel or trencher can be deadly. Also, avoid placing pipelines near trees. Not only will tree roots cause problems in the future, cutting a trench too close to a tree can cause the tree to eventually die.

Trenching:

Let us assume that you are using PVC pipe. The shorter pipe lines can be hand dug with a trenching shovel. For longer lines, you might need to rent a trencher. Be sure to follow the instructions to the letter. Think of a trencher like a large chainsaw that cuts through the earth. Stay clear of the moving teeth, as they can cause serious bodily injury.

We recommend trenching by hand placing the sod (grass) on one side of the trench
and the dirt on the other so when it comes time to bury the trench you will be
able to put all the dirt back and then puzzle piece the grass back and make it
hard to notice you trenched the yard. See our section on trenching at the
following link

www.SprinklerWarehouse.com’s Trenching

Piping:
In some areas, the pipe is installed deep enough that it won’t freeze. This is primarily done in southern states. In northern states, the pipe is generally installed with blow out connections so that the air can be removed before winter sets in. In any case, place the pipe at the depth recommended for your area.

When cementing pipe, be sure to cut the pipe square and clean off any burrs. Be sure to use primer on the fittings and then apply the cement while the primer is still wet. Purple primer is used by many contractors because of its visibility and is required in some areas. When connecting pipes together, be sure to measure carefully and make square connections. Pipe joints that are in a bind will eventually fail.

Valves:
Valves should be installed in a large enough box that they can be easily maintained. Some folks like to see how many valves they can fit in one box. This is a bad idea. Valves will eventually need to be repaired or even cut out and replaced, so leave room to work. If you are using spray heads and have lots of pressure, it is a good idea to install a fixed rate pressure regulator downstream of the zone valve to cut the pressure down. Spray heads typically mist and waste water at pressures higher than 30 psi. If you do this, make sure the regulator is properly sized for the flow delivered, and make sure there are no other valves downstream.

Sprinkler Wiring:
Unless prohibited by local code, you can place the sprinkler cable in the same trench as the pipelines. Wherever the cable comes up out of the ground to go into the house or up to the controller, be sure to place it in a conduit to protect from damage by the weed whacker. For most residential applications, 18 gauge multi-stranded cable is the right product to use. For larger properties, though, a bigger gauge might be needed. Do not use smaller gauge doorbell wire. It is not designed to be buried and will eventually give you trouble. Be sure to use waterproof splices that are filled with silicone where you make your connections to the valves. Other types of splices will fail. In most installations, you will use the white wire as the common. The common wire connects to all valves via one of the two wires leading to each valve. You will need to connect the other valve wire to its own individually color coded wire. At the other end of the cable, you will generally connect the white wire to the common terminal screw and the proper colored wire to each station. If you are using a rain or freeze sensor, you may need to make some changes. Consult your controller and sensor manuals for best results.

Installing Sprinkler Heads:
When you install a sprinkler head, it is best to install it on a flexible swing joint. This way you can place the head at grade. Some people like to use cutoff nipples. These are cheap and easy to use, but when the pipe eventually sinks, it pulls the head down with it. Then the head is below grade. When the nozzle retracts, it sucks in dirt and debris and eventually the nozzle clogs. The other possibility is dirt getting stuck in the seal. Then the head gets stuck in the up position and eventually run over by the lawn mower. Just use a swing joint, install the head at the proper grade, and avoid this problem.

Also when installing heads, place them several inches away from the house, fence, and sidewalk. This makes it easier to avoid overspray. Heads placed against the sidewalk will be damaged by an edger.

Backfilling the Trenches:
When backfilling the trenches, pile the dirt up gently on top of the trench, but don’t tromp it down just yet. Carefully distribute the soil and then you can “water pack” the ditches. Take a piece of pipe and attach to a garden hose. Turn the water on low and poke the pipe down into the bottom of the ditch. Watch as the soil begins to sink down into the ditch. When you start to see water appear, move on to the next spot. Don’t apply so much that the ditch starts to get muddy or water flows out of the ditch. You just want to apply enough that the soil starts to settle in the ditch. Once you have settled what you can without making a mess, put on a pair of rubber boots and “walk the ditches”, being careful not to sink in! If you put too much water on, you might get stuck. Once you have completed this step, you can rake a bit more dirt onto the ditches. If you do this right, you won’t have settling problems later.

Nozzle up the Sprinkler Heads:
Before putting nozzles on the heads, turn on each station to flush any dirt out of the lines. Once you have flushed the lines and are certain each valve is operating properly, install the correct nozzles. Double check to make sure heads are straight and installed at the proper grade. Adjust the arc and throw to make sure only the grass and landscape is being watered. Change nozzle sizes where necessary to avoid watering the house, the fence, or the street. Once your system is complete, call for the system to be inspected, if applicable.

Finally, measure the precipitation rate of each zone and water each zone according to its needs. Remember that the needs of the plants will change throughout the seasons. You can calculate the precipitation rate for each zone by measuring the flow rate through the meter in gallons per minute. Take this number, divide by the square feet in this zone and multiply by 96.3. This will give you the average precipitation rate for this zone in inches per hour.

After your system is installed, maintain it regularly. You can have a beautiful landscape and save water with a well-designed system that is properly installed, operated, and maintained.

Again, I hope this is of some value. As always, please help preserve our
water resources, and irrigate responsibly.

Filed under: Irrigation Installation | Tagged: | 2 Comments »

Understanding Lawn Sprinkler Systems

Posted on August 23, 2009 by SprinklerWarehouse

These are the basic components of a residential irrigation system, aside from design standards and techniques, I hope this will help you understand the individual components of the system and the function they perform.

a) Water Source

Familiarize yourself with where the water comes from for your irrigation
system. Many areas are now using recycled or “reclaimed” water for the purpose
of watering turf grasses and landscaped areas. Ask your builder or homeowners association if your home uses this type of
water and where you would expect to shut it off in the event of an emergency or
for maintenance issues.

Some areas are still using municipal or “city” water for irrigation. If this
is the case, instead of one, there will be two, back-flow prevention devices near
the water meter itself. They are typically at least 12″ off the ground and are
made of bronze. One of these two devices would be for the sprinklers and the
other one would service the home. This is where you would turn off the water for
your sprinklers.

Even though they are becoming a little more restricted, some homes have their
own well and pump or they may pump water from an adjacent lake. In either case
there will be related pumping equipment to supply water for your sprinklers. If
you are not sure how to stop the water flow from the pump, be sure and speak
with your irrigation professional. If the system is not shut down properly
severe pump damage or failure could occur.

Finally, some areas or developments have a large pumping station that delivers
water to the entire subdivision. As with the reclaimed water scenario, make sure
you know where to shut the water off for your individual property.

b) Controller/Timer

Your sprinklers will either operate from a controller located on the interior
or exterior wall of the garage, or they may operate from a central control
system. In some cases where a single residential property has its own pump, the
controller could be located near the pumping equipment.

In the event that you have an individual controller for the property,
familiarize yourself with how to switch the power off to the controller.
Sometimes this will eliminate an emergency situation in the event that the
sprinklers will not shut off. Irrigation controllers require high voltage to
operate them, you should not have to remove any screws or take anything apart.
If a malfunction of the controller is suspected, it should only be serviced by your irrigation professional.

c) Rotary Sprinklers

Any given property may or may not have rotary sprinklers installed. They are
generally used in large turf areas that are 20′x 20′ or more. They will shoot a
large stream of water and will oscillate back and forth slowly. Rotary
sprinklers operate on the same basis as the older impact or “knocker head”
sprinklers, but most of them are gear driven these days, which makes them much
quieter.

d) Stationary Sprinklers

Stationary sprinklers or “spray heads” are used in smaller turf areas and may
be used in landscape beds as well. Spray heads pop up out of the ground but do
not move. They spray more of a mist, compared to rotary sprinklers. Spray heads
come in 4″, 6″ and 12″ heights. The size that is used depends on the type of
turf grass or the sprinklers specific location in a landscape bed. The
landscaped areas of the home may also have what is referred to as a standpipe.
These are nothing more than a spray head nozzle attached to a fixed riser in order to attain sufficient clearance over the closer plants so the water can
reach the distant plants.

e) Drip/Low Volume Irrigation

Low Volume or “Drip” is commonly used in landscape and planting beds. Most
drip irrigation products use numerous emitters that are closer to the root zone
of the plants. However each emitter lets out a very small amount of water
compared to a spray head. This makes the watering process a very efficient
operation, because you are targeting only the specific areas that you want to
water. The water is applied at a much lower rate, reducing run off and you don’t
lose your water to the wind or evaporation. Drip irrigation is mandatory in many
areas. If you don’t see any water spraying in the planted areas around the home
chances are that drip has been installed.

In almost all cases, drip irrigation zones require a pressure regulator and
filter. The orifice that emits the water is very small, therefore making it very
prone to clogs from foreign matter in the water. More on the filter will be covered in the maintenance section.

f) Flood Bubblers

Flood bubblers are only used under certain circumstances. They come in fixed
rates and there are also adjustable bubblers. A fixed rate bubbler is ideal
because you actually know how much water your going to apply to the plant it’s
designed for. Bubblers may be used where large trees are located on the top of a berm where run off, or good saturation is a concern. The most common place you
would find one on a residential home would be in a very small planting area.
These areas are generally under the coach light on the same side of the garage,
as the font door of the home.

g) Rain Sensing Devices
Rain sensing devices or “rain sensors” are devices that cease all watering in
the event sufficient rainfall is detected. They are usually located near the
controller, sometimes on the eave of the roof or mounted on conduit pipe in the
landscape bed. Rain sensors have been mandatory components of an irrigation
system’s in many states for several years now and should be checked for proper operation
regularly.

h) Control Valves

Almost all irrigations systems have an individual control valve for each
station or “zone”. They are usually located at random intervals around the home
with only the lid visible. The lid on most control valves will be about 6″ in
diameter and green or purple in color. The purple lid indicates that the water
comes from a non-potable source; most often this means it is reclaimed water. If
there is a considerably larger box that is rectangular in shape it may house
multiple control valves or the filter for the drip irrigation if applicable.
Aside From filter maintenance, the control valves should only be repaired by
qualified persons.

Again, I hope this is of some value. As always, please help preserve our water resources, and irrigate responsibly.

Filed under: Irrigation Design, Irrigation Installation | Tagged: , | 3 Comments »