How to choose a correct size for the airless spraying tip?
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What do the numbers on the nozzle mean? How can you tell that the nozzle has worn out and needs to be replaced?
Airless spraying tips are very important part of the airless spraying system. They decide the spraying pattern width, how much paint are you spraying, the quality of the finish and the amount of overspray while doing the painting job. Wrong tip size may cause some painting jobs unnecessarily difficult, or in some cases just plain impossible to do. The correct understanding of few basic rules when choosing the airless spraying tip - it's one of the first and most important things every painter has to understand and master.
Important to remember - airless tip nozzle size combined with the spray pattern width decides the spraying area and the thickness of paint on surface.
Spray tip wear
Before starting a painting job you need to keep in mind that the tip you will be using will influence not only the time you will take to finish the job but also the quality of the finish. If the tip size is chosen incorrectly or the tip has worn out - paint thickness may be not even on the surface and the quality of the finish won't look professional.
In the table above, you can see what happens to the airless spraying tip when it wears down. When the nozzle is wearing down the width of the pattern is narrowing, and the hole in the nozzle gets bigger, so you will take longer to paint a certain area and you will use more paint to do it.
Unfortunately it is hard to predict the exact lifetime of a tip, because the it depends on the specification of the paint (solid particle percent, abrasive material) and of course how does the painter takes care of his tips - does he cleans them and if he does it correctly and thoroughly.
Airless spray tips marking
Usually airless spraying tips are marked using three number combination, for example - 517.
5 - This is the width of spraying pattern. To find out what width it is just double the first digit of the number and you will get its width in inches when spraying 30 cm away from the surface.
That means 5xx airless tip will paint 5x2= 10" width, which is 254 mm.
17 - is the size of the orifice. To get the exact nozzle size number, just take these two last digits and divide them by 1000. That means that this tip has a nozzle of 0,017" or 0,43 mm.
All in all - 517 tip, has 225 mm spraying pattern width, and 0,43 mm orifice.
Spray tip fan width and orifice size examples
The larger the orifice with the same fan width, the greater the volume of paint applied to the area.
The larger the fan width with the same orifice means the same amount of material is being applied over a greater area. The result is less volume of paint per square inch.
