An airless gun does not use compressed air. A pump sends coating to the gun at very high fluid pressure, the trigger opens a valve, and the coating is forced through a very small tip opening (the orifice), which breaks it into a fine spray. The orifice sets how much is delivered; the fan angle sets the width.
Fluid pressure does the atomising
The name explains it: airless spraying has no air jet breaking up the coating, as a conventional air spray gun has. Instead the sprayer's pump pushes the coating along the hose at very high fluid pressure, and the gun's only job is to release it through the tip on demand. When coating at that pressure is forced through a tiny opening, it shears into a fine mist that travels to the surface.
That is why the gun is only part of a pressure system. The pump, hose, gun, tip guard and fittings all carry the same pressure, and none of them may be asked to hold more than its rating. Titan's rating for the RX-80 and RX-Pro guns is 3600 psi, and the RX-Apex is rated for 5000 psi. The weakest rated part in the system sets the limit.
What the trigger does
Between the gun inlet and the tip sits a valve that the trigger opens and closes. With the trigger released, the valve holds the pressure back. With it pulled, coating flows to the tip. Titan's RX and S guns use a ball valve and seat for this. On the RX-Pro, the ball valve kit is 0538221 and the seat is 594-033. Titan describes the S-3 as having a tungsten carbide ball valve and seat.
You will not need to think about the valve until it wears. A gun that leaks or spits at the tip after you let go of the trigger is telling you the valve is no longer sealing, and on the RX-Pro Titan's manual points to replacing the ball valve and reversing the seat. The parts for each model are on its own diagram page, reached from Titan Spray Guns, Tips & Accessories.
The tip: orifice and fan
The tip is where the work happens, and two things about it matter. The orifice, the size of the opening, controls how much material is delivered. The fan angle controls how wide the pattern is. Thicker coatings generally need larger orifices; fine finishes use smaller ones.
Both are stamped into the tip number. Take the first digit and double it for the fan width in inches at 12 inches from the surface; the last two digits give the orifice in thousandths of an inch. A 517 therefore gives a 10 inch fan and a 0.017 inch orifice. With the same orifice, a wider fan spreads the same amount of coating over more area, so the film is thinner. The reversible 695-517 is an example of a 517, and the other sizes are reached from our airless spray tips page.
Why a worn tip costs efficiency
Coating wears the tip as it passes through. As the orifice grows, the same pump pressure is released through a larger hole. Pressure falls, the pattern turns coarse or streaky, and more paint leaves the gun for the same area covered. That is the whole mechanism behind the common advice to replace tips when the pattern degrades.
The tip seal behind it matters too, since it is what keeps coating from leaking round the tip. Seals are on our Titan Seals page, such as the 651-020 tip seal.
Why the pressure is dangerous
A jet of airless fluid can inject coating through the skin. It can look like a small cut, but it is a serious medical emergency: get immediate medical attention and tell the doctor what the fluid was.
- Never put a hand or finger over the tip, and never point the gun at any part of the body.
- Never test the spray on skin.
- Keep the tip guard fitted. A common choice is the 0289228 tip guard; all four Titan guards are on the Tip Guards page.
- Engage the gun's trigger lock whenever you are not spraying.
- Follow the pressure relief procedure in your model's manual before changing a tip or servicing anything.
Where this leads
Airless is one of three ways a gun can atomise. HVLP uses turbine air at low pressure for fine finishes, and air-assisted airless adds a small amount of air to fluid pressure for finer atomisation at lower fluid pressure. The guns post covers when each suits; this one is only the airless principle. For sizing, the tips posts go deeper. If you have a gun in front of you, start from its model page on the Gun, Hose and Tip Kits page, such as the 0538006 RX-80 or the 0550065 S-3 kit.
Parts mentioned in this guide:
The Short Version
Pump pressure pushes coating to the gun, the trigger valve releases it, and the tip orifice breaks it into a spray while the fan angle sets the width. A worn orifice wastes paint, and the same pressure that makes the spray can injure you, so keep the guard on and the lock engaged.
Need a tip, seal or valve part?
Call (713) 931-0006 with your gun model and our parts team will confirm the part before you order.
(713) 931-0006Order by Parts Diagram