Smithco Turf Spraying Guide - Manual (Page 12)

Raindrop Hollow Cone Nozzles Size RA-2 through RA-6 require 50 mesh screens
Raindrop Hollow Cone Nozzles Size RA-8 and larger does not require strainers.
Turbo Floodjet Nozzles TF-VS2 through TFVS-3 require 50 mesh screens. Turbo Floodjet Nozzles
TF-VS4 and larger do not require screens.
• Always be alert to the possibility of a plugged or damaged nozzle. Serious misapplication may
result.
• Check nozzles out-put periodically.
D – AGITATION
he question often comes up whether hydraulic or mechanical agitation is superior. There is
really no correct answer. Both are very acceptable if they perform the required job. That is to
keep the insoluble materials use suspended in the carrier. The oft time feeling that mechanical
is better stems from the fact that it became popular when fiberglass tanks and small volume
piston-diaphragm pumps became popular. Because the small volume output of the diaphragm pump
precluded the use of hydraulic agitation, mechanical means had to be devised. These were
considerably more expensive, due to the cost of the pump, as well as the costs associated with
fiberglass tanks and stainless steel mechanical systems. Over time, the more expensive systems
became misconstrued as superior
The point is, as long as there is enough volume to provide adequate turbulence to keep particulate
matter suspended, there is no difference in quality of agitation. To further this end, devices such as
“Venturi” tips or “Eductor” nozzles continue to reduce the differences in effectiveness. These nozzles
literally double to triple the flow through them by “Venturi” action.
The case could be made that mechanical agitation is considered inferior as the need to have rigid walls
to mount shafts, packing glands to prevent leaks and extra horsepower to turn the shafts are required.
E – SPRAY CONTROLLERS
he spraying industry have grown considerable more sophisticated since the days of the “Ratchet
Valve” was the standard to turn spray booms on and off. Today, computers are being used more
and more to control the spraying event. They have become popular because they increase
efficiency and productivity, especially in large scale operations. The level and sophistication of
these devices brief descriptions of the various controllers in use today. Remember that computers
really only do two things: 1. Monitor and adjust flow to keep application rate constant as it senses
changes in ground speed; and 2. Keep track of volume sprayed and acreage covered.
Computers can be either “flow” based, “pressure” based or in one unique instance, both.
Smithco is not a supporter of pressure based control systems due to the earlier explained loss
of pressure due to friction through lines, fittings and solenoids. Pressure based systems would
be accurate only if the pressure transducer was placed at the tip, and then only for that tip.
Most systems mount the transducer up around the solenoids, so they are only relatively
accurate. That is, they will accurately read and report pressure and pressure changes where
the transducer is mounted, but that may have nothing to do with what is going on at the tip.
When do you have forty PSI at the tip on a boom mounted with 8008 nozzles? Only
when that tip delivers eight tenths of a gallon in one minute!
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