How To Select The Right Spray Nozzle
A comprehensive guide to spray nozzles
What are spray nozzles?
Spray nozzles are essential components in a variety of spraying applications, from agriculture to amenity maintenance. Their main function is to control the distribution, droplet size, and coverage of liquid as it's delivered from a sprayer. Choosing the right nozzle type ensures efficient application, minimizes waste, and helps achieve consistent results.
How to choose the correct nozzle for your sprayer
Choosing the right spray nozzle depends on several factors, including the type of application, spray pattern required, flow rate, and the specific chemicals being used. For amenity and turf care, two popular options are anvil nozzles and flat fan nozzles.
These produce a thin, fan-shaped spray pattern ideal for even coverage over flat surfaces. They’re widely used for applying herbicides and fertilizers on lawns, sports pitches, and golf courses. Their design is particularly suited to use on spray booms as the tapered edges of the spray pattern helps to minimize overlap and reduce chemical waste.
Anvil nozzles are engineered to produce larger droplets and reduce drift, making them suitable for applications where precise targeting and drift control are required. They are particularly effective when wind is a concern or when treating small, specific areas.
Understanding nozzle colours and sizes
Spray nozzles are colour-coded to indicate their flow rate and capacity. This international standard makes it easy to select the correct nozzle for your desired application rate. For example, red typically represents a flow rate of 0.4 gallons per minute (GPM) at a standard pressure.
Selecting the right nozzle size is crucial. Consider your sprayer’s operating pressure, the speed at which you’ll be moving, and the volume you want to apply per hectare or acre. Manufacturers provide charts to help match nozzle size with these variables.
Rotary vs. Spray Nozzles: What’s the difference?
Rotary Nozzles
Rotary nozzles use a spinning action to produce larger droplets and a coarser spray, which helps reduce drift. They’re best for situations where drift control is a priority and can be especially useful for uneven terrain or taller crops.
Spray (Flat Fan or Anvil) Nozzles
These nozzles provide a consistent, fixed spray pattern - ideal for uniform, close-to-ground applications such as turf or amenity spraying.
The best choice depends on your application needs: rotary nozzles for drift reduction and varied terrain, spray nozzles for even coverage and precision.
How to attach and change a nozzle
Most modern sprayers use quick-release fittings or threaded connections for attaching nozzles.
To attach:
- Ensure the sprayer is depressurized and off
- Remove the old nozzle by unscrewing it or releasing the fitting
- Clean the fitting and insert the new nozzle, tightening securely
- Check for leaks and alignment before use
Nozzles should be checked regularly for wear or blockage and replaced if needed. Change your nozzle when you notice uneven spray patterns, reduced output, or after a set number of spraying hours as recommended by the manufacturer. Regular maintenance extends equipment life and ensures accurate application.
If you are spraying using a knapsack type or handheld spryer, you may want to carry out a trial spray using water alone first so you can regulate your walking speed and check the spray quality.
The role of spray guards
Spray guards are attachments that shield the spray pattern, reducing drift and preventing spray from reaching unintended areas. They are particularly useful in sensitive environments or when applying chemicals near non-target areas, such as paths, water courses, or flower beds.
FAQs
Q: How often should spray nozzles be replaced?
Replace spray nozzles when they show signs of wear, such as uneven spray, reduced flow, or after a number of spraying hours recommended by the manufacturer. For heavy use, check and replace at least once per season.
Q: What is the difference between an 80-degree and a 110-degree nozzle?
The angle refers to the spray pattern width. An 80-degree nozzle produces a narrower, more concentrated spray, while a 110-degree nozzle provides a wider coverage, ideal for overlapping passes and uniform application.
Q: What is the most powerful pressure nozzle?
'Most powerful' depends on the pressure rating and flow rate. High-pressure nozzles deliver finer droplets and greater force, but the best choice depends on your application and equipment specifications.
Q: What PSI should a spray nozzle be?
Most spray nozzles operate efficiently between 2-4 bar (30–60 PSI), though the ideal pressure varies by nozzle type and application. Check manufacturer guidelines for your specific nozzle.
Q: Does a smaller nozzle increase pressure?
No, a smaller nozzle restricts flow, which may increase velocity but not system pressure (which is determined by the pump). Using a smaller nozzle at the same pump pressure results in less output volume, not higher pressure.