Spruce up sprayers for spring
As spring approaches, so does the need to prepare your turf equipment for the season ahead. A few hours spent now with your turf sprayer will pay dividends throughout the spraying season.
You want your sprayers in tip-top condition to ensure that you're applying products accurately and limiting the waste and drift of pesticides. As the cost of pesticides rises, inaccurate applications mean wasted money, as well as an increased danger to the environment. Off-target drift can damage neighboring property and result in an inadequate amount of product finding its target.
The sooner you start pre-season maintenance the better. This will allow your dealer time to get needed spare parts before the season starts. You'll quickly recover the cost of new nozzles, pressure gauges or check-valve diaphragms after a few hours of correct application.
A well-maintained sprayer will apply pesticides correctly and more efficiently, work without breakdowns and minimize waste.
Where to start As you go through these maintenance steps, always keep in mind these warnings: Take great care when adjusting a sprayer while the engine is running; always engage the handbrake when leaving the seat; and be sure you're wearing protective clothing to avoid contamination.
The power unit must be powerful enough to operate the sprayer efficiently under all working conditions. Carry out routine service as outlined by the manufacturer in the operator's handbook. Maintenance should include cleaning or replacing the air cleaner to ensure the engine maintains the correct power output. Change the engine oil and filter if necessary. Check tire pressures to ensure even boom height and positive steering. Grease bearings and hinges as recommended.
The sprayer unit: Partly fill the tank with clean water and move the sprayer to an area of waste ground. Remove the nozzles. Wear a coverall, gloves and a face visor when working with the sprayer as it may be contaminated. Engage the drive mechanism. Increase the speed slowly to operating revs. Test the on-off and pressure relief valves, and check the agitation system. Flush the spray lines, then switch off the engine. Refit the nozzles and check the liquid system again for leaks.
Maintenance checklist Check the pump, plumbing, booms, nozzles, tank and controls for wear and tear. Use a methodical approach-follow the flow of water from the tank to the nozzles.
Check that the tank is thoroughly clean, with no sediment in the bottom. Look for fractures and any other damage. Make sure the tank sits securely in its mount and that the agitation is working effectively.
Check hoses for splits, chafing and cracks, particularly at bends in the line. Examine the connections to ensure they are water-tight.
Check the pump for leaks, which often occur at hose connections and on the input shaft. Make sure that the pump rotates freely. Check if a pulsation chamber is fitted and make sure the air pressure is at the recommended level.
On filters or strainers, look for leakage, missing filter elements and seals, and blocked or damaged filters. Make sure you have the correct filter for the nozzle size.
Make sure the control circuitry (electrical or hydraulic) is operating correctly. Examine valves for internal and external leaks
Be sure the pressure gauge needle doesn't fluctuate when the nozzles are spraying, and that it returns to zero when the sprayer is switched off
Check the movement and stability of the boom, and its folding and height adjustment mechanism. Check that the boom breaks away as it should to avoid damage to the boom if you inadvertently strike an obstacle.
Boom piping: Inspect the condition of all hoses and pipes for splits, chafing and cracks, particularly where the booms fold. Look at the nozzle bodies for damage or loose fit. Check for leaks under pressure. Replace any damaged units.
Make sure all valves stop liquid flow from the nozzles when you switch off the sprayer. Look for damaged diaphragms and seats.
Make sure all nozzles on the boom are the same, are in good condition and have no evidence of streaks or irregularities in the spray pattern. All nozzles should be clean and free from obstruction. Clean nozzles with a soft brush or airline-don't risk damage by using wires or pins. Make sure all nozzles deliver to within 5 percent of the manufacturer's chart value.
If your sprayer has automatic controllers to monitor the speed of the sprayer and the flow, pressure and area sprayed, check that they are in good condition and properly maintained, and that they are calibrated frequently for accuracy. Look for leaks, blockages, variations in pressure or any minor damage during spraying.
Routine maintenance You must check sprayers regularly to ensure that they are receiving proper maintenance and need no repairs. Before attempting any work on a machine, make sure that the brakes are applied and that all necessary protective clothing is on hand.
Routinely carry out the following checks: * All hoses must be tightly connected and free from sharp bends; replace cracked or damaged hoses * All controls must move freely and be fully adjustable. * The pressure gauge should read zero. * You should be able to turn the pump over by hand. * Make sure drain plugs and clean filters are in position. * Tires should be sound and correctly inflated; and wheel nuts should be tight.
Dr. Andrew Landers is the pesticide application technology specialist in the Department of Agriculture and Biological Engineering at Cornell University, Ithaca, N.Y.
Calibration is a vital part of preparation. Operators simply haven't time not to calibrate. You should do it before the spraying season begins and in the middle of the season. You should calibrate for each intended application rate.
A recommended calibration technique:
* Read the label.
* Measure the forward travel speed of the sprayer with the booms out and over the field to be sprayed. Mark a distance of 100 feet on grass. Record the time taken to drive over the course. Speed (mph) = distance (ft) x 60/elapsed time (seconds) x 88.
* Calculate the nozzle output per minute required:
Target gallons per minute (gpm) = gallons per acre x mph x nozzle spacing (inches) /5,940
* Select the appropriate nozzle set.
* Set the correct pressure at the gauge by using the pressure-regulating valve.
* Collect and measure the output of each nozzle for 1 minute. The output of each nozzle should be about the same as calculated in the equation above. Remember there are 128 fluid ounces in 1 gallon. If output has been calculated at 0.27 gpm then output is 128 multiplied by 0.27, or 34.5 fluid ounces in 10 minute.
* Replace all nozzle tips that are inaccurate by more than 10 percent.
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