Lawn sprinklers are a huge convenience; their efficient and time-saving function makes a huge difference to our garden-keeping efforts, and they are certainly recognizable. If not for the many film scenes in which hopeless romantics or well-endowed heroines get a midnight golf course soaking, then for the many homes in each neighborhood that feature the distinct sound and sight of a sprinkler in action.
But how do sprinklers work exactly? Many of you may be familiar with fire extinguishing sprinkler systems, fixed to the ceiling in office blocks and warehouses, but the inner workings of garden sprinklers are somewhat more complex.
Workings of the Oscillating Sprinkler
The most commonly used type of sprinkler is the oscillating sprinkler; these units are placed on top of the lawn and spray a ‘curtain’ of water across the grass. The arm oscillates forward and back to cover a large rectangular area, (often around 20X30ft).
On oscillating sprinklers there is a knob which is used for the adjustment of the water spray pattern, connected to this is an arm which is pulled and pushed by a ‘heart-shaped cam’. When the sprinkler is in operation the ‘cam’ rotates very slowly (roughly at around 1rpm), and it is this which causes the metal sprinkler arm to oscillate back and forth. The metal sprinkler arm has an O-ring seal to keep the connection watertight, and screws straight into the body of the sprinkler.
The Underground Sprinkler
These sprinklers act as a more permanent solution to your lawn watering needs; the underground sprinkler system requires a network of piping to be buried around 12 inches underground, to feed water to the retractable heads that site in certain areas of your lawn.
The heads are activated by a pressure system, when the water travels through the pipe it pushes the heads up above the ground where they spray the surrounding lawn. Once the water supply stops, the heads drop beneath the ground again and the spray stops. Raised head sprinklers are the most common attachment to underground systems, the heads stand tall when raised from the ground to avoid being blocked or affected from foliage. These systems can be bought with an added ‘rain sensor’ so the system ‘knows’ when it is not required to automatically pop out and water the lawn.
These systems are operated by an electronic controller which is attached to a box of valves, buried underground. The mains water enters the system via this box and is then divided into different ‘zones’, each of which is controlled by an individual valve. Each zone’s water is sent off and is distributed through the above ground sprinkler systems.
The workings of these sprinkler systems make for truly brilliant and convenient products, and with such hot summers in some parts of the world, it’s best to keep your lawn in tip top shape!