Use the Xeri-Cap to cap off the remaining sprinkler heads
What is an overhead / broadcast watering irrigation system?
Overhead irrigation is any spray or rotor sprinkler system that broadcasts water into the air.
What is a drip watering irrigation system?
Drip irrigation is a type of highly-efficient irrigation where water is delivered from the irrigation pipe directly to the soil
at the root zone of the plant.
Check your local Water Company for possible rebates available for home watering system conversion projects.
Drip Irrigation
Drip irrigation works by distributing water directly to the soil at a very low rate (in gallons per hour) from a system of small diameter plastic tubing fitted with outlets called emitters or drippers. Drip irrigation is highly efficient because the water soaks into the soil before it can evaporate or run-off. The water is also applied close to the plant root zone providing a high moisture level in the soil in which plants can thrive.
Why Use Drip Irrigation?
A properly designed and installed drip irrigation system can achieve up to 90% irrigation efficiency. This can significantly reduce your water use. Drip irrigation also allows you to:
- Match the water application rate to each plant
- Apply water directly to the root zone of the plant
- Eliminate runoff, overspray and evaporation
- Reduce disease problems associated with moisture on some plants
- Improve plant health by irrigating efficiently
- Prevent damage to property such as asphalt windows, walls, and fences
Benefits of Drip Irrigation
- Water the plants you want to grow not weeds
- Easy to install
- Can be inexpensive
- Reduces disease problems associated with moisture on some plants
- Promotes healthier plants by increasing its size and overall quality
How to Convert a Sprinkler System to Drip Irrigation System
- Locate the spray head you wish to convert
- Remove the top of the spray head by twisting it and removing the whole internal assembly
- Insert the new 1800-Retro internal assembly and drop it into the existing body. Make sure to tighten the top.
- Use Easy Fit Compression Fittings to attach the drip tubing.
- Use the Xeri-Cap to cap off the remaining sprinkler heads.
Drip Irrigation Components
The main components of a drip system consist of a mainline, valve, backflow preventer pressure regulator, filter, tubing adapters and fittings, drip tubing, emitters and an end cap. They are divided into four categories: control zone components, distribution components, emission devices and tools.
Control Zone Components
Controls the quality of water (filter), whether the system is off/on (valve), and the pressure of the system (pressure regulator).
Valves:
Turns the water flow on or off through the pipe. There are two types of valves: an isolation valve which is operated manually or a control valve which is automatic and is usually electric-powered using a solenoid.
Backflow Preventer:
A backflow preventer is a device that prevents any unwanted contaminants from being sucked back into the main drinking water line. All irrigation systems must have a backflow preventer at all times. Check with your city on which type to use.
Pressure Regulator:
A pressure regulator keeps the water pressure coming to your home at a constant level. Since water pressure can vary throughout a water district, building codes require houses to have a pressure regulator on the water line going into a house (usually set between 50-60 psi). Most irrigation systems do not have pressure regulators installed. Drip irrigation systems are designed for very low pressures (20-30 psi) and require a pressure regulator. They are usually
installed after the filter.
Filter:
A filter in a drip system is a must because it keeps dissolved substances such as small grains of sand from clogging the emitters over time. There are two types of filters: disc filters and screen filters. It is recommended to use a filter with a 150 to 200 mesh. It is best if the filter is installed between the control valve and the pressure regulator.
Distribution Components
Delivers the water reliably, safely and efficiently to each outlet.
Tube Fittings:
Fittings are plastic connectors such as couplings, tees, ells and adapters that attach the drip tubing to other tubes and to the rest of the drip system. There are two types of fittings: barbed fittings in which the tube goes over the fitting and compression fittings where the tube slides inside the fitting and holds it in place. Barbed fittings are best used when you are going to bury your tubing and compression fittings are best used when they are not buried.
Drip Tubing:
Drip tubing is a special thin-walled tubing made out of polyethylene which has a low pressure rating. The common sizes for a drip system are 3/4”, 1/4”, or 1/2”.
Emission Devices
Emission devices control the application of water to the plants.
Emitters:
Emitters are small plastic devices that control how fast the water drips out onto the soil. They can either screw or snap onto a drip tube or pipe.
Flush Valve or End Cap:
It is important to cap the end of the drip tubing because without it the water will run out at the end of the drip tube. It is important to keep in mind that tubes sometime develop sediments or algae over time so it is recommended to flush out the drip tubing once a year.
Tools
These tools are needed in order to install the drip irrigation system fast and efficiently
How to Install a Drip Irrigation System
How to Start
1)Determine the water source for the drip system. If you are converting an existing sprinkler system to a drip system using a retro-fit kit follow the guidelines. If you are converting an existing valve follow these instructions.
A) Locate the valves which are usually around the outside wall of the house or typically in a green irrigation control box.
B) Add the filter and the pressure regulator after the control valve and connect it to the main supply line.
2) Determine the drip method you wish to water the plants. There are two basic ways:
A) Point Source:
- Watering of specific plants through emitters or bubblers.
B)Total Coverage (Broadcast):
- Where 100% coverage is required by using in-line drip tubing or micro-sprays.
3) Lay out the supply line of 1/2” tubing between the base of the plants. Make sure to have enough tie down stakes to help keep the tubing in place or else it will tend to curl and make installation difficult. Use fittings to connect the tubing wherever the tubing has to turn at a sharp angle or branch out to another section.
Things to Keep In Mind
Length/Flow:
Limit the supply line to about 200 feet per zone because the longer the line is the more pressure it will lose. Also the more emitters installed the more pressure you will lose.
Elevation:
Take into account that elevation affects water at about 0.433 psi per foot change. For example if you are running a supply line that rises 10 feet in elevation from the valve to the end of the line you will lose about 5 psi (10 feet x 0.433 psi) going up a 10 foot slope.
Emitters:
You cannot use the same size or number of emitters for all plants. Smaller plants will need lower flow or fewer emitters. Larger plants will need higher flow or more emitters.
Maintenance:
Once a month, check the system for leaks and plugged emitters. Also remember to remove and clean the filter.
4) Install the emitters at the base of the plants at about 9”- 12” apart inches on center. Keep in mind that if you are installing the system for existing plants that have already been established then you would place the emitters throughout the root zone of the plants. There are two ways to install emitters.
A) You can use a punch to open a hole in the main supply line and then insert the emitter
or
B) You can insert the emitter directly if it comes with an insert barb that is sharp enough to be punched through the line without using a punch.
5) Flush the system before you run it by leaving the end of the tubing open and letting the water out. This will remove any soil or debris that may have gotten into the system during installation.
6) Close the end of the supply line by bending over the end of the tube and using a figure-eight end cap
7) You can bury the tubing by adding a layer of mulch on top to hide the tubing and keep water from evaporating.
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