Impact sprinkler
An Impact sprinkler (sometimes called an impulse sprinkler) is a type of Irrigation sprinkler.
Contents |
[edit] Development
The original horizontal action impact drive sprinkler was invented by Los Angeles citrus farmer Orton Englehardt in 1933 and patented in 1935 (US Patent #1,997,901). Orton later sold it to Clem and Mary LaFetra who manufactured and marketed it under the brand name Rain Bird.
[edit] Design and operation
 |
This article may be confusing or unclear to readers. Please help clarify the article; suggestions may be found on the talk page. (February 2009) |
The sprinkler pivots on a bearing on top of its threaded attachment nut. It is driven in a circular motion by a spring-loaded arm pushed back by the water stream which returns to "impact" the stream.[1] This breaks up the water stream enabling a uniform watering area around the sprinkler.
Some full-circle impact heads feature a second, short range, opposing "spreader" nozzle (see image), which fills the close range watering coverage role provided by the rapid "return cycle" on part-circle heads.[1]
The uninterrupted flow path of impact heads makes them less vulnerable to damage and clogging by dirt and sand in the water. Thus, they are suitable for systems fed by well water. One defining feature of impact heads is they almost always have male pipe threads, as opposed to the female threads found on virtually all other sprinkler types.
The sprinkler head was originally manufactured from metal. Since the 1970s, they have also been manufactured from thermoplastics for improved corrosion resistance.
[edit] Usage
The impact sprinkler's long throw radius and uniform water distribution re-creates the effect of natural rainfall, and the device quickly replaced[citation needed] the centuries-old technique of furrow irrigation, in which trenches were dug between rows of crops and flooded.
[edit] Variations
An underground pop-up version of the impact sprinkler was introduced as a way to avoid the problem of having to carefully and time consumingly mow around overground sprinkler heads.[2] When not in operation, these sprinklers disappeared out of sight below turf level.
Although largely replaced by gear-driven "rotor heads" by the 1990s, impact sprinklers still have many advantages, including uniformity of coverage, sand and grit resistance, and operation at lower water pressures.[3]
[edit] References
- ^ a b "Publication: Operating Characteristics of Center Pivot Sprinklers". Ianrpubs.unl.edu. http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=360. Retrieved 2008-12-17.
- ^ "Landscape Irrigation Equipment Part 1: Sprinklers & Spray Heads - HGIC @ Clemson University". Hgic.clemson.edu. http://hgic.clemson.edu/factsheets/hgic1810.htm. Retrieved 2008-12-28.
- ^ Barrett, James; Brian Vinchesi, Robert Dobson, Paul Roche, David Zoldoske (2004-01). Golf Course Irrigation: Environmental Design and Management Practices. John Wiley & Sons, Inc.. pp. 84. ISBN 978-0471464556. http://books.google.com/books?id=2Ka1CPTimZEC&pg=PA84&lpg=PA84&dq=impact+sprinkler+design&source=web&ots=RbDK52pDZg&sig=jezNBNQM97y9coEOgT1tmArW8wo&hl=en&sa=X&oi=book_result&resnum=2&ct=result#PPA84,M1.
