What Is a Sprinkler?
Sprinklers are devices that are connected to a water source with a hose or pipe and use water pressure to spray water in droplets over a wide area.
Some sprinklers are capable of spraying solutions mixed with fertilizers or pesticides. Generally, sprinklers are installed outdoors on the ground, but in greenhouses and buildings, there are various types, such as ceiling-mounted or suspended sprinklers.
Uses of Sprinklers
Sprinklers are widely used for irrigating crops, fruit trees, lawns, plants, and green curtains; spraying pesticides; and cooling vinyl greenhouses, barns, buildings, and barn roofs by spraying water. Other uses include firefighting, where sprinklers originated, dust control at various stadiums and work sites, snow melting on railroad tracks, and bait sprinklers in the fishing industry.
Features of Sprinklers
Advantages
The advantage of sprinklers is that they can sprinkle water over large areas or slopes that are difficult to move without much effort. Additionally, even though they are inferior to drip irrigation, they can effectively irrigate small amounts of water in the form of rain or mist-like droplets, making it easier for plants to absorb water.
Disadvantages
The disadvantage of sprinklers is that they can be affected by wind, especially outdoors. Another drawback is that the amount of water applied can be uneven depending on the location.
Types of Sprinklers
1. Classification by Sprinkler System
Rotating Type
There are two types: the full-circle type, which rotates 360 degrees to sprinkle water, and the fan type, which can sprinkle water on only a part of it. The impact type is installed on the ground, and the arm flaps around due to water pressure. It is the most common type, has the widest range of uses, and is available in a wide variety of types.
The pop-up type is used for lawns, roadside green belts, plantings, etc., and is installed embedded in the soil. They lift and spray water underwater pressure only when in operation, can be used at low pressure, are light and compact, structurally simple, and have the advantage of being trouble-free. Rain gun-type sprinklers are characterized by their ability to sprinkle water over a large area, such as a large stadium or factory.
Other types include the ball drive type, in which a ball inside the sprinkler moves with the water flow, and the piston type, in which a piston built into the main body rotates to spray water more evenly than the impact type.
Swivel Type
This type of water sprayer moves in a linear, repetitive motion forward and backward (left and right) to spray water evenly in a rectangular shape.
Mist Fountain Type
Spraying water in the form of mist, this type is used for sprinkling water on lawns and for cool mist showers.
Tubular
A drip tube is also called a drip tube. It is placed directly on the ground.
Widely used in agriculture and other fields. The watering range is 1 to 3 m wide, but care must be taken to avoid twisting the tube, which not only prevents watering but can also cause damage. Also, the durability is not good, and the watering holes may widen due to deterioration.
2. Classification by Functional Aspect, Material, and Accessories
Watering distances range from about 1 meter for sprinkler tubes to more than 25 meters for large rain guns. Pressures range from as low as 0.3 MPa to as high as 0.4 to 0.7 MPa.
The angle between the ground and the watering nozzle is called the elevation angle, which is most widely used in agriculture and ranges from 23 to 27 degrees. For watering trees and roofs, the angle is 10 degrees or less. Conversely, a high elevation angle of 40 degrees or more may be used for watering slopes and dust prevention at various work sites. Variable elevation angle types are also available.
The most common materials are metal, which is durable, and resin, which is often used in smaller types. Resin is less durable than metal, but engineering plastics are as strong and durable as metal. In agriculture, riser pipes (rising pipes) are sometimes connected to accommodate crop height.
How to Select a Sprinkler
It is important to choose a sprinkler by following these steps:
- Calculate how many meters of water will be sprayed based on the size of the sprinkler area.
- Select a sprinkler that is appropriate for the distance to be sprinkled and consider the appropriate installation interval.
- Check the water pressure required for sprinkling, the water discharge per minute, and the size of the bore diameter of the sprinkler by referring to the performance chart.
- Select the equipment that meets your needs based on the pump, piping, distance from the water source, and budget.
Sprinkler catalogs indicate performance charts, but if you are installing large equipment, you can consult with a contractor for a quote. The amount of water needed depends on the crop. For example, in the case of seedling cultivation, care should be taken not to apply too much water, as it will damage the seedlings.
For large areas, such as several hectares, a rotating impact type or a pop-up type that can spray water over a wide area with a watering distance of 20 meters or more is useful. For home flower beds and small vegetable gardens, a small type with a watering distance of 5m or less or a spray or tube type will suffice. If there is a ceiling, such as in a plastic greenhouse, it is necessary to devise a way to prevent the water from hitting the ceiling before use.
Sprinklers are not only for fixed installation but also for one-touch detachable types or those that can be hand-held or installed on a vehicle to sprinkle water while moving. The more manual element requires less budget, but the more labor and time it takes. It is important to choose a sprinkler that fits your purpose and budget.
How to Use Sprinklers
Sprinklers should be checked for damage or clogged nozzles before installation. If the sprinkler is to be installed over a large area, it is a good idea to draw up a layout plan. It is recommended that a filter be installed between the water source and the sprinkler to prevent clogging of the sprinkler.
Automatic water sprinkling is also possible by setting a timer to open the water source. When mixing fertilizers or other chemicals in the water, a liquid fertilizer mixer should be installed between the sprinkler and the water source. Furthermore, if the water pressure from the water source is too high, a pressure-reducing valve may be connected between the sprinkler and the sprinkler.
If the water pressure from the water source is strong enough, many sprinklers can be operated at once, but if the water pressure is low, partial sprinkler operation will result in sequential water spraying. Even within the sprinkler’s range, the amount of water sprayed is often somewhat uneven from place to place, so care must be taken in placement to ensure a uniform amount of water is sprayed.
Furthermore, since sprinklers are affected by wind, the effective sprinkler distance should be approximately 60-80% of the sprinkler distance, and the sprinkler spacing should be determined. It is also important to slowly close the plug after use to prevent damage due to water hammer action.