How to Choose the Nozzle

How to Choose the Right Nozzle for Your Airless System


In this simple and practical guide, we want to show you some useful tips to operate at your best and give you the correct selection criteria for this small but very important component.

Mounting the right nozzle on your Airless Paint Sprayer will allow you to increase your performance, keep costs under control by minimising waste and achieve a high-quality result, whatever your application or the material you want to use.

The first suggestion, the easiest, is to check the specifications contained in the datasheet or the product’s label you want to apply. Usually in most of the materials sold there is a section where the recommended nozzle hole size is indicated.

As the viscosity or particle size of the product to be sprayed increases, the size of the nozzle orifice must be increased.

NB: Numerous DIY airless equipment in the large DIY distribution do not have sufficient flow and pressure to perform important work with the appropriate nozzle sizes. If you have any doubts about which model to buy, please contact our specialist

What the airless nozzle is for and how to distinguish the various types

The nozzle has the function of dispensing the high-pressure material inside your Airless sprayer. Through the small orifice placed at its end, the nozzle determines the working intensity of the paint sprayer, the correct spray amplitude of the paint and the adequate flow rate of the fluid.

A wide variety of sizes of airless nozzles are available, very different in technical characteristics and performance, each of which is designed for particular applications. To distinguish them, you can refer to some parameters:

  • The first digit on the nozzle: is indicative of the width of the fan and therefore of the covered surface: it corresponds to the spray angle. When, as in the photo for example, the number 4 means that the nozzle produces a spray with a fan equal to 40 degrees. If you multiply this number by 5 you will get how much surface you cover with the spray standing 30 cm from the object (example: 4 x 5 = 20 cm). If you need to paint a wall, for example, it is advisable to use a wide spray angle that can cover a wider surface. Typically, nozzles with a fan size of 40 or higher are used. For more detailed spraying, such as railings, poles or columns, a nozzle that allows for more accurate nebulisation is preferable, thus opting for a 10 or 20-degree fan.
  • The last two digits on the nozzle are usually odd and indicate the size of the spray hole in thousandths of an inch. In the example, the 25 will indicate 0.025″. The higher this number, the higher the flow rate of the fluid. If you have a 425 airless nozzle, you can benefit from a higher flow than you would with a 423 nozzle. Please also remember that the size of the orifice is also linked to the amount of paint sprayed. The flow rate of the material naturally also depends on the pressure (the higher the sprayed paint flow rate) and the type of product used (the heavier the material, the lower the flow rate).

NB: Each Airless paint sprayer model has a maximum nozzle measurement limit that you can use

How To Choose The Airless Nozzle Based On The Application

We have mentioned the hole measurement as one of the discriminants of choice for the Airless nozzle. Let’s now see how to take advantage of this feature in practical terms, that is, starting from the application for which you will have to use your sprayer:

  • For painting work on wood or metal: the ideal nozzle for enamels and paints will have a minute hole from 0.009″ to 0.015″. Grip agents generally require smaller sizes than those you will use later to spray the product onto them.
    If you want a nozzle that allows you to achieve high-quality finishes, you can now choose the innovative Fine Finish version equipped with an integrated pre-atomiser that reduces particles by more than 25% compared to a standard nozzle, using lower pressures. You can recognise it from the white butterfly.
  • For interior painting work: you will have to choose a nozzle whose size is between 0.017″ and 0.023″. Super washable, glazes and wall primers will need a 0.017″ nozzle, washable paints for apartments or offices one 0.019″, to paint the sheds where usually greater coverage is needed rather than the finishing a 0.021″ hole and finally the tempera is applied with a 0.023″ orifice.
    To improve efficiency we have created Low-Pressure nozzles that allow you to achieve optimal misting with up to 50% lower pressure. This reduces the risk of bounce spraying, makes it easier for you to control the spray, and ensures a longer life for the nozzle itself and the paint sprayer when subjected to less strain. You can spot them from the green butterfly.
  • For external painting works: the ideal nozzle for siloxane or quartz paints with a very fine flour will be 0.023″ or 0.025″ if the particulate is larger than 0.027″.
  • For airless fillers: This product is an exception. Applied with our most efficient Testarossa Superquindicimila Airless paint sprayer that guarantees an exceptional flow rate of 13 l/min, the 0.019″ or 0.021″ nozzle size is usually preferred (quite small compared to the high viscosity of this product), to allow you to obtain a very smooth finish that allows you to save on sanding work, very expensive both from the point of view of operator fatigue and for the subsequent cleaning of the environments. Any need to have a greater thickness on the surface will be easily and quickly achievable by giving subsequent additional coats of the product.
  • For waterproofing sheaths, intumescent paints, coatings and other high viscosity materials: nozzle sizes with the widest hole must be used. We advise you to contact our technicians who will be happy to help you make the best choice!

How is the airless nozzle made?

The airless nozzle is designed to spray the material with the desired density, quantity and width of coverage. The Airless paint sprayer sends it at the desired pressure and then sends it to the pistol equipped with the base with the relative nozzle (also called butterfly). It consists of:

  1. A shaped plastic handle, in different colours (Red for the Standard version, White for the Fine Finish series, Green for the Low-Pressure type) showing the size of the nozzle. The arrow indicates the direction of the spray. Turning it to 180° places it in position to remove any obstructions that have come to plug the hole (hence the name of the self-cleaning nozzle).
  2. A steel cylinder
  3. A tungsten carbide tablet (the actual nozzle).

The Nozzle Base

The base is the housing on which the nozzle is fixed and then screwed to the gun or its extension. It consists of:
  1. A ring nut: its thread is usually available in two sizes. The European standard we have adopted is 11/16″ (if you want to check the one supplied on your gun, just measure the diameter that will be about 17 mm). There is also the American 7/8″ (about 22 mm) that we do not market
  2. A base: in black plastic contains the seat where to place the nozzle (butterfly).
  3. A kit of gaskets (cartridge): is used to guarantee the perfect seal. If you notice a paint leak from the base, the kit is likely damaged or its replacement is quite simple: just completely unscrew the base and insert the butterfly on the front, between the two stop flaps, pushing gently until the entire cartridge comes out. The new kit must be put back in place paying attention that the concave part coincides with the seat where the nozzle is inserted.

Some final tips to get the most out of your Airless nozzle

Now that you have all the information you need to choose your Airless nozzle, remember that using it will allow you to experience its full potential in a person and, of course, also to evaluate its performance.

If, for example, the painting operations lead to excessive material consumption, you can solve the problem by increasing the spray angle or by using a nozzle with a smaller orifice.

If you notice that you do not cover enough of the surface, you will have to increase the size of the nozzle hole or decrease the fan.

Finally, the utmost attention is paid to recognising the signals that indicate that your nozzle is now worn and therefore needs to be replaced: this situation occurs due to the abrasive action of the material and increases if there is a hard particulate in it.

A worn-out Airless nozzle produces an uneven spray, the covered area will be uneven and with less amplitude causing an increase in operating times and a worse quality of finish. In addition, with the widening of the nozzle orifice, a direct consequence of its extreme wear, you will notice a greater consumption of materials.

On average, it is estimated that a worn Airless nozzle will waste up to 30% more paint than a new one: therefore, do not hesitate to replace it!

Do you need more information or a dedicated consultation to choose the perfect nozzle for your Airless paint sprayer?

Ask for support for a consultation or a dedicated quote