Installation | Lasting Impressions Landscape

Installation

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.

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.
    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.