How to properly clean agricultural sprayers

By Stara

Proper cleaning of agricultural sprayers is one of the key steps in ensuring the efficiency, precision, and safety of pesticide handling. Accumulated residues compromise nozzles, filters, and hoses, cause application failures, and increase the risk of soil and crop contamination.

In addition to preserving the operator's health, proper cleaning extends the lifespan of agricultural machinery and maintains the quality of operations, preventing blockages, corrosion, and drift.

In this guide, you will understand how to clean your agricultural sprayer completely and safely, which products to use, when to perform each step, and which Stara technologies help in this routine.

Why is cleaning an agricultural sprayer essential?

Pesticide residues compromise the uniformity of application and can alter the dose delivered to the soil or plants. This directly affects pest control, product efficiency, and crop health. Lucas Luersen, an agronomist at Stara, reinforces this:

"Proper adjustment ensures precision in distribution, accurate rates, and even extends the machine's lifespan."

This same principle applies to the cleaning of agricultural sprayers: any residue accumulated in the tank, filters, or nozzles compromises the uniformity of the spraying. Therefore, keeping the equipment clean ensures benefits such as: prevention of blockages and line failures; reduced wear on hoses, valves, and spray nozzles; protection of the crop against chemical residues from the previous operation; and greater agronomic efficiency and better use of pesticides.

When the sprayer is not cleaned properly, some of the previous spray solution may remain in the system. In subsequent applications, these residues mix with the new product and can cause phytotoxicity in the crop, with symptoms such as leaf spots, burnt edges, or reduced plant growth.

This risk increases, for example, when the equipment alternates between herbicides, fungicides, and insecticides, or when there is a change of crop in the area. Thorough cleaning of the tank, filters, hoses, and nozzles reduces this possibility and helps preserve the stand, vigor, and productive potential of the crop.

When should sprayers be cleaned?

Cleaning should be carried out whenever there is a risk of residue buildup. This includes:

- before the first application of the day, ensuring the tank is free of residue;

- after each use, to prevent drying and the formation of deposits;

- when switching products or categories, such as herbicide to fungicide;

- at the end of the workday, preserving the system for the next job.

If the sprayer is left unused for extended periods, perform a thorough cleaning to prevent residue buildup.

Step-by-step guide to properly cleaning agricultural sprayers.

Proper sprayer cleaning prevents clogging, maintains a stable flow rate, and preserves application quality, avoiding phytotoxicity. A structured routine ensures consistent performance and prevents field failures. Check out the step-by-step guide.

1. Complete emptying of the syrup.

Empty the tank completely in a suitable location, following environmental practices and the proper disposal procedures for leftover spray residue.

This step prevents unwanted chemical reactions between products and reduces the risk of scale formation. Always confirm that the line is also empty before proceeding to pre-washing.

2. Internal pre-wash

Circulate clean water through the system to loosen residue stuck to the tank walls and free coarse particles from the pipes. Pre-washing facilitates the action of the detergent in the next step and reduces the chance of filter clogging.

Maintain recirculation long enough for the water to reach the ends of the system in a clear state.

3. Tank cleaning

Open lids and inspection points to reach the inner walls. Use a detergent specifically designed for sprayers, scrubbing with a suitable brush to remove chemical residue and crusts.

Rinse until the water runs completely clear, ensuring that no residue remains that could alter the next mixture or compromise the dosage.

4. Washing hoses, filters and valves

Remove filters, wash each part separately, and check for cracks or blockages. As Luersen reminds us:

Mishandling errors can cause blockages in fertilizers, seeds, spray solution, and machine channels.

Proper cleaning prevents exactly this type of problem.

5. Cleaning the spray nozzles

Remove the nozzles and wash them carefully. Never use metal or pointed objects, as this will alter the jet geometry. Use:

- running water;

- soft brush;

- Appropriate detergent, if necessary.

Take the opportunity to check for natural wear and tear on the nozzles, as small deformations increase the volume applied and raise costs.

6. Final rinse with recirculation.

Perform a complete recirculation with clean water, ensuring the entire system is free of debris.

This step confirms that detergent, particles, and product residue have been completely removed. If the final water is cloudy, repeat the rinsing process until the desired clarity is achieved.

7. Final Test

Perform an agricultural spraying test using only water to validate its operation. Observe if the pressure remains stable, if all nozzles show the same droplet pattern, and if there are no defects in sections or valves.

This test identifies problems before returning to the field. As Luersen reinforces:

"The operator must calibrate and adjust the machine step by step, calmly. This is what guarantees a good result."

Cleaning follows exactly this logic: method and attention.

External cleaning of the agricultural sprayer

In addition to internal cleaning, caring for the exterior of the sprayer helps preserve components, paint, and structure. Stara offers specific products for this routine, suitable for machines that work in constant contact with oil, grease, pesticides, and fertilizers.

ST Clean

In situations of heavy soiling, use ST Clean degreaser, developed for heavy-duty cleaning of agricultural machinery.

Before using ST Clean, wash the machine with warm water up to 40°C or, if that's not possible, with plenty of water. Then, dilute the product according to the level of dirt:

- Heavy soiling: 1 to 1 ratio, that is, 1 liter of ST Clean in 1 liter of water;

- Moderate soiling: a ratio of 1 to 5, that is, 1 liter of ST Clean in 5 liters of water.

Apply the product with a spray gun, let it sit for about 5 minutes, and rinse thoroughly, avoiding any buildup of debris. Then, let the machine dry in a place protected from direct sunlight, always respecting the label instructions.

ST Film

To protect the structure against oxidation, use an agroprotective product. ST FilmIt forms a waterproof film on the sprayer surfaces, increasing the machine's lifespan and making future cleaning easier.

ST Film should be applied using a spray gun to a clean, dry surface. After application, allow to dry completely, avoiding contact with water or dirt during this period. The first application is done at the factory. Reapplication is recommended every 500 hours of operation or after using ST Clean degreaser.

Whenever you need to replenish ST Clean or ST Film, the producer can visit the nearest Stara dealership, ensuring the use of products approved for the brand's sprayers.

6 things to keep in mind when cleaning

Some errors go unnoticed during sprayer cleaning, but they directly compromise the efficiency of the next application and the durability of the product. Cleaning must follow a rigorous standard to avoid mechanical damage, spray failures, and even cross-contamination between products.

Avoid:

1. Use metal tools on the nozzles;

2. Mixing pesticides without performing a thorough rinse;

3. Leaving residue in the filters;

4. To carry out the process in a hurry;

5. Ignore contaminated external points;

6. Using unsuitable detergents.

Choosing the right product makes all the difference in the cleaning result. In the next section, see which products are truly suitable for cleaning agricultural sprayers safely and efficiently.

Recommended cleaning products

Cleaning efficiency depends on using the right products. Common detergents can damage hoses, seals, and nozzles. Therefore, it's ideal to use solutions developed for spray systems, capable of removing chemical residues without harming the components.

Some recommended products are:

- Specific agricultural detergents: remove herbicide, insecticide, and fungicide residues. Prevent incrustations and reactions between different spray solutions;

- Chemical residue neutralizers: essential when the sprayer alternates products. They eliminate remaining molecules and reduce the risk of phytotoxicity;

- Cleaners specifically designed for nozzles and filters: loosen dry residue without altering the nozzle orifice, preserving the droplet pattern and flow rate;

- Mineral deposit removers: important in regions with hard water. They dissolve limescale and prevent pressure loss.

Safety during sprayer cleaning

Cleaning agricultural sprayers involves direct contact with chemical residues and sensitive equipment parts. Therefore, safety must be treated as part of the process, not as an afterthought. Attention to procedures reduces the risk of contamination, accidents, and harm to agricultural machinery operators.

Good safety practices involve:

- Use complete PPE (Personal Protective Equipment);

- Wash the equipment in a well-ventilated area;

- Avoid splashing when opening filters and valves;

- Follow the label instructions;

Keep your distance from people and animals.

How to avoid cross-contamination?

Cross-contamination occurs when residues from the previous application remain in the system and interfere with the next application. To avoid this, thoroughly clean the tank, hoses, filters, and nozzles, following the correct order of emptying, pre-washing, washing, and final recirculation.

Respecting the rinsing cycle indicated by the manufacturer ensures that the sprayer is ready to receive a new spray solution, maintaining a precise and uniform application.

Technology to facilitate the cleaning and maintenance of sprayers.

The Imperador line of self-propelled sprayers was designed to make the operator's daily work easier, including routine cleaning. The continuous recirculation system keeps the spray mixture homogeneous during operation and reduces the accumulation of residue in the piping, which simplifies the cleaning process after use.

The nozzle-by-nozzle shutoff and electronic spray control help identify flow variations, blockages, and nozzle malfunctions before they become bigger problems. These early warnings allow the operator to target cleaning to critical points and avoid waste in the next application.

With Topper, it is possible to monitor pressures, sections, and operational parameters, ensuring that each cleaning step is validated before returning to the field.

If any doubts arise during the process, the operator can rely on Conecta, a remote technical assistance service that helps interpret warnings and identify inconsistencies in the system.

Cleaning ensures precision and a longer lifespan for the agricultural sprayer.

As we've seen in this content, cleaning the sprayer is an essential step to ensure the efficiency, safety, and longevity of the machine. Clean equipment preserves nozzles, filters, and valves, reduces field failures, and ensures more precise applications.

With good practices, technology, and proper maintenance, the producer increases the efficiency of the operation and protects their investment in the field.

Other questions about cleaning agricultural sprayers

How many liters of water should I use?

The volume varies depending on the tank's capacity, but good practice is to use between 10% and 15% of the total capacity per rinse cycle, ensuring that the system is thoroughly cleaned.

Is it necessary to disassemble the filters and nozzles?

Yes. Disassembly allows for the removal of accumulated residue inside the parts, something that washing by circulation alone does not remove.

What happens if you don't wash it properly?

Lack of cleaning alters the working pressure, modifies the applied dose, and compromises uniformity. This reduces efficiency and can generate undesirable effects in the crop.

Can compressed air be used to unclog drains?

No. Compressed air can deform the orifice and alter the droplet pattern. The correct way is to use running water, a soft brush, and a specific detergent when necessary.