"On Target Application with Superior Drift Control"
A. Length should not exceed 75-80% of total rotor diameter or wingspan for optimum drift control. Your state will mandate your boom length allowable. In testing, the Accu-Flo Nozzle has shown excellent results at 100% of Rotor diameter, almost negligible changes from 75% of rotor diameter. See study by Ivan W. Kirk and W.C. Hoffmann Paper Number 02-AA06 [PDF]Operational Factors Influence Spray Drift and Deposition from Helicopters
B. Accu-Flo™ Radial Nozzles, 9 styles are available. They are lightweight (2 oz. ea.), easy to maintain, durable, and produce a large number of uniform droplets, thereby greatly reducing drift. Their main disadvantages are a two second trail-off after shut-off, and dirt trapped under the seal if In-line strainers are ineffective.
C. Nozzles optimally should be spaced every 6” along entire length of boom (Spacing the nozzles further apart may cause “striping” at lower altitudes. Up to 12" spacing is allowable at higher altitudes, but remember that this will reduce your output and coverage, and you need to recalculate).
D. When installing the nozzle assembly on the boom, make sure the mating threads are clean and in good condition. Use of WD-40 aerosol spray is recommended for cleaning and lubrication. A small amount of petroleum jelly may be rubbed on the o-ring before putting the nozzle onto the assembly to ease removal later. If the o-ring binds during removal, twist cap back and forth 2 or 3 times to free up. (Avoid gobs of petrolium jelly that can wash into the flow and clog needles.) Tighten sufficiently to stop any leak at attaching point. Gaskets are NOT required at the boom outlet, but teflon tape can be used if desired. Channel-Loc pliers may be used carefully if required. A rubber strap wrench may be helpful in disassembly.
E. Extremely low or high flow rates are best achieved by careful selection of nozzle cap and restrictor. The recommended operation range is 23 to 40 PSI.
F. There are several important maintenance issues. Effective straining of spray mix is absolutely imperative for trouble free operation. Insufficient or inadequate strainers will cause nozzle dripping. In-Line strainers (100 & 200 mesh) MUST be in good condition and diligently maintained. If using Accu-Flo™ check valves, install a 1” diameter 80 mesh dish-shaped screen at each of the nozzle fittings on the boom. 100 mesh strainers are also available for Spraying Systems check valves. Boom must be adjusted to provide a smooth air flow over the boom. Periodic flushing with CLEAN water pays big dividends. Flushing the boom and nozzles should be done at maximum pump pressure (Not exceeding 70 PSI).
G. Wettable powders and thickeners are not recommended in the smaller size Accu-Flo™ nozzles in general, but can be used if you have proper tank agitation. Flushing nozzles after spraying is recommended to prevent buildup of powders in equipment. Smaller nozzles are considered to be the .020 and .016 orifice sizes.
H. Service any dripping nozzles promptly. Manual cleaning of removed Accu-Flo™ nozzle check valves may be accomplished with a stiff bristle tooth brush by depressing the plunger to expose the rubber seal. DO NOT tamper with spring tension. It is preset for proper opening and should not be changed.
Bishop Equipment offers a reconditioning process on a time and materials basis that completely cleans and straightens needles, replaces o-rings and damaged parts, and tests for proper operation. This service is offered year round, but your winter down time is a good time to get this process done to avoid interruptions during your spray season, and discounts are often offered between December and January for this service. See Products and Services for more information. (Reconditioning Information)