Sprinkler System Installation
Hunter Preferred Contractor
Controllers
A device that turns an irrigation system on and off at a desirable
time and operates the system for a preset period of time. In
essence, it “controls” the system…hence, the name.
Hunter units offer exceptional reliability. Power outages have no
effect since the watering schedule is held in non-volatile memory
and backup batteries are unnecessary. The controller is easily set
by turning dials or pushing buttons, giving the user the ability to
select such functions as when watering will start, how long each
zone will water and what days watering will occur. Adjustments and
bypasses can also be made for seasonal changes and inclement
weather.
Electronic controllers have the capabilities to meet the needs of
today’s sophisticated, water conscious landscape designs. In
addition, they can be programmed to apply water in short cycles,
preventing run-off in the most steeply sloped areas.
Sprinklers
Today’s modern sprinkler systems include sprinkler heads of two
types: spray heads and rotary heads. The types of heads utilized on
a specific project will be determined by the dimensions of the area
being covered, the water pressure available for operation, and a
variety of other factors.
- Spray Sprinklers
These are usually what are most commonly envisioned when a
homeowner thinks about a sprinkler system. These heads are
dispersed around the lawn and in planting beds.
The spacing between sprinklers can vary depending upon the
specific nozzle installed in the head, but they rarely are
spaced further than 15 feet apart. Spray sprinklers installed in
turf areas are designed to pop-up during watering and retract to
below the turf line to allow mowing and normal use of the lawn
after watering. Spray sprinkler bodies are commonly available in
various sizes, the difference being the height that the spray
apparatus or nozzle is lifted above the body of the head. The
high-pop-up models are used for flower and shrubbery bed areas
where risers might be unsightly or subject to damage from
passerby.
- Rotary Sprinklers
These sprinklers are larger devices that are used in open,
uninterrupted spaces that allow water to be dispersed 25 to 30
feet or more. These heads typically pop-up during use and
retract after operation in lawns or other areas with foot
traffic. They are also available in fixed (non-pop-up) versions
for use on risers in large planting areas.
Hunter rotary sprinklers operate on a gear-drive technology.
Water turns a small turbine in the base of the unit which drives
a series of gears, causing the head to rotate. The gear drive
mechanism is sealed from dirt and debris, and operates without
the irritating clatter of traditional impact sprinklers.
Gear driven rotors are easy to adjust and factory sealed to keep
contaminants out. Although the individual rotor unit is several
times more costly than a spray head, its wider spacing
capabilities means fewer heads are needed to cover a given area.
- Sprinkler Nozzles
The nozzle is the device that water passes through as it leaves
the head to be dispersed onto the
landscape. Irrigators rely on different nozzles to vary the
quantity of water dispersed during the watering cycle, as well
as the distance that water is to be thrown by each head. The
amount of water distributed over a given area per minute can be
doubled or tripled by choosing the correct nozzle.
Valves
Zone valves are the mechanical devices that turn the water on and
off to the individual sections of the system. Water meters and water
service lines cannot provide enough water to water an entire yard at
once, so the system is typically broken up into several individual
zones or stations.
The concept of “zones” also allows the professional irrigator to
group areas (e.g., flower beds, turf) based on watering need (e.g.,
full sun, part shade). Valves are typically installed near the area
they water. Sometimes valves can be installed above the ground and
grouped in a “manifold” near a water source.
There are two basic types of valves being used today:
- Manual Valves: Seldom installed today, manual valves require
a person to turn them on and off (with a wrench or valve key).
Existing manual valve systems can be easily upgraded to
automatic control by a professional contractor.
- Automatic Valves: No need to keep a mental note when to turn
these valves on or off, as they are operated by the electric
controller. Wires run in the ground along with the main line
pipe to the valve and are connected to the controller. When the
controller sends the current to the valve, it opens. When the
current is cut the valve closes.
Sensors
How sensors work is quite simple: they interrupt the electrical flow
from the controller that would otherwise activate the valve. The
sensor does not interfere with the controller’s program.
- Rain Sensors
These units are mounted in a location exposed to normal
rainfall, but outside the watering spray of the
sprinkler system. Rain will trigger the device, causing the
system to remain off during or after an event if sufficient
precipitation is measured. The rainfall settings can be adjusted
so that a light shower will not affect system operation, to
avoid eliminating a scheduled watering when rainfall is not
sufficient to make up for a normal application.
- Freeze Sensors
This type of sensor is very popular where ice on walkways or
streets can cause liability, as well as in gardens where
watering before or during heavy freezes can create problems with
ice laden shrubs and trees. The freeze sensor interrupts the
signal to the control valves when temperatures fall below
freezing. Once conditions improve, the system will return to
normal operation.
- Flow Sensors
This type of sensor helps to identify a break in the system
before any damage can occur. A rupture pipe or a broken
sprinkler left undetected can flood the ground, erode slopes,
even undercut driveways and sidewalks. A flow sensor is set to
activate at a specified level of flow; once that level is
exceeded, the circuit is broken and the valves are shut off.
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