An Irrigation System consists of numerous different components that come together to make an efficient watering system. These components consist of a Supply Line, Water Meter, Manual Valves, Backflow Prevention Devices, Electric Valves and Manifold, Lateral Piping and Fittings, Sprinkler Heads, Drip Irrigation and Micro Irrigation, Controller, and Wiring.
Supply Line
When it comes to your supply line it is usually a water line coming in from the street, you can also use a pump and pump out the body of water. You will want your supply line to be made of heavy-duty material. The supply line or mainline supplies the irrigation system with water and is usually under constant pressure. Usually, you will want to use a municipal poly as it’s rated for high pressures, demonstrates impact and abrasion resistance, freeze-break resistant properties, and is corrosion resistant. The longer maintenance-free life cycle allows for fewer system breaks, water loss, and costs for those using municipal poly.
Water Meter
Water meters record water use. They are usually installed by the city or municipality you live in. They must be installed before the irrigation connection and before your backflow prevention device. Typical water meters are 5/8 and 3/4 inches. Some commercial water meters can be up to 4 inches. Some are totalizing (record volumetric use only), and others have a flow rate indicator.
Manual Valves
Having a manual valve before your backflow is important for installation and maintenance. The common kind of valves used for the manual valve is either a brass ball valve or a brass gate valve. Gate valves allow for great control over the speed and amount of water entering the system. They also create a small amount of friction loss when fully open. Ball valves are often used for isolation valves, you should take great care when opening your ball valve as they are a quarter-turn valve and can create a water hammer if opened too fast.
Backflow Prevention Devices
Backflow preventers prevent any contaminants from flowing or back siphoning into the city's potable water supply. Some kind of backflow prevention device is required on any irrigation system. They are a legal requirement for all municipal connections. Irrigation systems are considered low-hazard systems unless injecting chemicals like fertilizers. Please check with your local code when it comes to the proper types of backflow prevention devices needed for your municipality.
There are multiple different types of backflow prevention devices seen in irrigation typically these are some of the different types.
HBVB (Hose Bib Vacuum Breakers) Are the simplest kind of backflow prevention device. These are typically used with drip and micro systems, HBVB’s are attached to the hose bib on a house and are a non-testable backflow device you generally do not want to use these on automatic systems.
DCA (Dual Check Valve) A DCA is a form of backflow prevention consisting of two independently acting spring-loaded check valves. A DCA is not a testable form of backflow protection and does not include shut-off valves. The DCA is less reliable than a DCVA and is used in non-health hazard applications. The DCA backflow prevention device is rated for constant pressure.
AVB (Atmospheric Vacuum Breakers) Allow air to enter the irrigation system when the zone is turned off. When you install an AVB you want to install it after each valve, they must be at least 6 inches above the highest point. These are a non-testable form of backflow prevention as well you must have at least one on each zone if you are using AVB’s. These are not a recommended kind of backflow prevention device.
PVB (Pressure Vacuum Breaker) Are similar to an AVB, but they have two ball valves, a spring-loaded poppet, and testable cocks. You may need to replace the internal components of your PVB every five years. O-ring gaskets that seal against the inner walls of the breaker might become brittle and crack over time. The plastic poppet and bonnet can also wear out over time. When these components malfunction or break, this can cause water to pour out from under the cap. When installing a PVB it needs to be installed 12 inches above the highest outlet. Only one is needed and it is installed on the pressure side of the valve.
DCVA (Double Check Valve Assembly) This form of backflow prevention is the most commonly used in irrigation. DCVA’s are for use in medium hazard situations in non-health hazard cross-connections and constant pressure applications that can be subject to backpressure or back siphonage situations. There are two single check valves in the body of the backflow device. These are a testable form of backflow prevention with four test cocks and two shut-off valves. All DCVA’s installed in residential irrigation will need to be tested tri-annually according to CRD you will have to consult your municipality code to see what your testing requirements are.
RPBA or RPVA (Reduced Pressure Backflow Assembly) Are similar to a DCVA as it has two check valves these check valves are independently acting spring-loaded check valves separated by a spring-loaded differential pressure relief valve, two seated shutoff valves and four test cocks. When operating the pressure between the two check valves is maintained at a lower pressure than the supply pressure. If there was ever a leak in one of the check valves the relief valve is designed to open and discharge the water outside. These are usually used in high-health hazard applications. An RPBA should be provided with proper drainage as it will periodically discharge small amounts of water due to the fluctuation of in-line pressure up or downstream of the backflow preventer.
Electric Valves
These valves can be used as a master valve or a zone valve. Electric valves are connected to your irrigation controller. Your controller once set up will tell your valves when to open and close with a solenoid. You can have either an electric 24V controller which you need AC solenoids for that or you can use a battery-operated controller that uses DC solenoids.
Valve Boxes
A Valve box is important when doing an inground system. A Valve box is needed for all the underground components so you can get access to them. Your valve box needs to be large enough to house your manifold and valves. You should have a separate valve box for your backflow preventer. You should have your valve box supported with bricks to prevent downward pressure on your piping. It’s best to have a layer of landscape fabric, with drainage rock over it to ensure your valves stay out of the dirt and the box doesn’t fill up with water.
Lateral Piping
Lateral piping is the line that runs from the solenoid valve to the sprinklers. The pipe size will vary on the amount of water (Flow Rate) required for the zone. The lateral pipe is only under pressure when the valve is turned on. The kind of pipe you use can depend on the application, it depends on whether it is under a higher pressure, exposed to UV rays, flex, and what is on top of the pipe. For most residential irrigation jobs, here at Wes-Tech we recommend using Blu-Lock pipe as it comes in rolls or sticks has flex, does not need clamps and glue, it’s environmentally friendly, and it’s a high-density poly so it can withstand higher impacts than the regular poly prime pipe and does not crack like PVC pipe can.
Fittings
Your need for different fittings will vary on the kind of pipe you use and the job. If you are using poly pipe you will need to insert fittings and clamps you should use crimp clamps as gear clamps can relax over time and cause maintenance issues, if PVC pipe you need PVC fittings, glue and primer, if using Blu-Lock pipe you just need Blu-Lock fittings, Blu-Lock fittings are similar to a shark bite fitting as they have teeth on the fitting that will grab on to the pipe and you need a removal tool to take it off. You can reuse Blu-Lock fittings unlike the regular insert or PVC pipe fitting.
Sprinkler Heads
When Selecting sprinkler heads for an irrigation system, consider which is best suited for your watering needs. Some important aspects are operating pressure, flow rate, distance/radius, precipitation rate, and arc coverage. When choosing a spray head or a rotor take the manufacturer's specifications into consideration as they can differ from manufacturer to manufacturer. When installing your spray heads or rotors there are a few factors you will want to consider for the area. Think about the size and shape of the areas you want to irrigate, plant types, microclimates (Wind, Temperature, and Precipitation), soil type, and slope of the landscape. You will want head-to-head coverage, this means each spray head spray touches the next one
Drip and Micro Irrigation
Drip and micro irrigation have made headways in recent years as it is generally not subject to water restrictions, you will have to consult your municipality as they can vary. When it comes to drip and micro irrigation you want to have a pressure regulator or a pressure reducer on your system between 20-40PSI that is the optimal pressure range for the irrigation, you will also want to have a filter on your system as drip and micro irrigation usually has small orifices and can get clogged easily. Even if you have clean water, you will always still get sediment that can clog these orifices. Note that even with a filter, plugged orifices can still happen. Drip is beneficial for the fact that it has a next to nothing evaporation rate as it waters the roots rather than spraying the plant. Drip and micro have the benefits of putting the water exactly where you want it.
Controllers
Controllers are the brains of your irrigation system. You need an irrigation controller to tell your zones when to turn off and on, how long to be on for and what days you want it on with a controller it is easy to customize your watering schedule for your needs. We recommend getting a smart controller like the HRC400 it is a Hydro Rain B-Hyve controller. The benefits of having a smart controller is that you can connect to the local weather stations and set it so when it rains your irrigation will not go off, so your smart controller can monitor weather, soil conditions, and evaporation. The B-Hyve controller lets you connect through your smart phone, tablet or computer. This controller comes in 8-16 stations had four programs A,B,C, and D, even if your power goes out your programming is safe as it has a non-volatile memory.
Wiring
Irrigation wiring is how your controller talks to your valves, when getting your irrigation wire there are a few things to consider, like wire run lengths, most wire manufactures have wire run length carts to help you decide which gauge of wire will work best for your needs. Take into consideration number of valves and if you want to have room to expand in the future. One of the important rules to think of when installing your irrigation wire, is always use the white coloured wire as the common, this makes it easier when wiring your valves as each valve will have its own colour, it also makes it easier for contractors to figure out the systems wiring routes. As well as each valve will be connected to its colour of wire that will be the same colour connected to the irrigation controller for the corresponding zone. Always use waterproof wire connectors for all the connections in the valve box. Never bury a connection even if you have waterproof wire connectors.
These are all the components that go into an irrigation system. If you have any questions about irrigation or the components please feel free to contact us using our contact us form or come into one of our locations to talk in person. One of our many knowledgeable employees will be happy to help.