Large Power-Driven Sprayers (low pressure)
These sprayers are designed to distribute dilute liquid pesticides over large areas. They deliver a low to moderate volume of spray -- usually 10 to 60 gallons per acre -- at working pressures ranging from 10 to 80 psi.
These sprayers usually are mounted on tractors, trucks, or boats, but some are self-propelled. Roller pumps and centrifugal pumps are most often used and provide outputs from 5 to more than 20 gallons per acre. Tank sizes range from less than 50 gallons to 1,000 gallons. The spray material usually is hydraulically agitated, but mechanical agitation may be used.
- medium to large tanks permit relatively large area to be covered per fill,
low pressure limits pesticide penetration and reach.
Low-pressure sprayers often are equipped with sprayer booms ranging from 10 to 70 feet in length. The most common booms are between 20 and 35 feet long and contain several nozzles. The height of the sprayer boom must be easily adjustable to meet the needs of the job. Boom supports should allow the boom to be set at any height from 12 to 72 inches above the surface being sprayed. Many nozzle arrangements are possible, and special-purpose booms are available.
Low-pressure sprayers that are not equipped with booms generally have a central nozzle cluster that produces a horizontal spray pattern. The resulting swath is similar to the pattern made by a boom sprayer. These sprayers are useful in irregularly shaped areas, because they can move through narrow places and avoid trees and other obstacles. Some low-pressure sprayers are equipped with a hose and handgun nozzle for applications in small or hard-to-reach areas.