WHAT IS HVLP?
~FACT & FICTION~
To qualify under the term HVLP, air flowing through the Aircap must not exceed 10 psi. Generally speaking, HVLP turbine motors produce over 100 CFM (cubic feet per minute) at 3 – 8 psi. (pounds per square inch) depending on the model of motor. Compare this to a typical high pressure set-up where 45 – 60 psi at 8 CFM would be the norm. HVLP turbines supply air at a much lower velocity producing a softer, easier to control spray. This allows you to lay the paint on gently and not blast it on. Benefits of HVLP include less overspray and less paint wastage. Transfer efficiency can be as high as 85%. The quality of finish is identical to the best high pressure spray finishes.
In some areas of the USA. (Southern California for instance) high pressure spray systems are prohibited in certain industries. All HVLP turbine systems, (by any maker) automatically comply with all known regulations in North America. HVLP is ‘Clean Technology’
There seems to be a lot of confusion about what kind of motor is used in the turbines. Standard built-in residential type vacuum motors are used by all HVLP makers. Although years ago a few systems were built with non-tangential motors, any industrial size HVLP turbine made in North America today will use a tangential motor.
HVLP makers typically give CFM specs ‘unrestricted’. The outlet on the Motor itself is 1 ½” and this is where 100 CFM plus can be measured. Once the outlet is reduced, the air is restricted so that only a fraction of the unrestricted air can possibly pass through the air cap of the Spraygun. If the area of the air holes (orifices) in a typical HVLP air cap are added together, the combined diameter will only be about 3/8″. Although much is said about how high the CFM rating is on these motors, the fact remains that because the pressure is low, only around 12 – 20 CFM passes through the Aircap anyway – the rest of the air is surplus. So unlike their high pressure counterparts, air leaks do not matter. In fact, using a ‘Y’ connector, 2 sprayguns can be attached to the turbine and no real loss of power will be noticed. At very low pressures, with this type of turbine motor, psi becomes much more important than CFM. The more pressure that is used, the more CFM passes through the Aircap. It is therefore the pressure that forces more air through the same Aircap. The result is better atomization with the higher pressure.
Although sealed pressure can be measured with a gauge, it is often highly inaccurate. True pressure is calculated by a simple formula. H20 Inches X .036 = PSI. Motor makers supply accurate measurements of the H20 Inches (amount of inches of water the motor can push up a vertical tube) for all their motors. Another indication of motor power is the Operating Amperage and wattage. UL and CSA rate the motors under actual use (spraying water), to determine the true operating specifications. The Fuji Mighty-Mite Model (discontinued) used a 2-stage motor that produced 110 CFM at about 4 psi. The operating Amperage was rated at 8.7 amps. The new Semi-PRO™ 2-stage motor is rated at 11.5 amps and a full 1400 watts or power. The Fuji Mini-Mite 3-stage motor’s operating amperage is rated at 11.5 amps. The Fuji Mini-Mite Model uses a 5.7″ diameter, 3-stage motor that is the most powerful in its class.
The 4-stage motor we use on the Q4 GOLD™, Super 4 GOLD™ and Mini-Mite 4™ is more powerful than that used by most HVLP Makers. A full 8.5psi pressure.