AGP AC023, Инструкции по безопасности

Страница: 16 / 36

16
instrument to clean the tip. The tungsten carbide
is brittle and can chip.)
SPRAY TIP SELECTION (See chart 1)
Spray tip selection is based on paint viscosity, paint
type, and job needs. There are two variables to
identify the tip: orifice size and fan pattern width.
The main variable is tip orifice size. Generally, use a
smaller orifice tip For light viscosities (thin materials,
like varnish), and use a larger orifice tip for heavier
viscosities (thicker materials, like latex paints).
Spray tip orifice size is based on how many gallons
of paint per minute can be sprayed through the tip.
Do not use a tip larger than the maximum pump
flow rate or capacity the sprayer can accommodate.
Pump flow rate is measured in gallons per
minute (GPM) and liters per minute (LPM).
The other variable is the fan pattern width. Two tips
having the same orifice tip size, but different fan
widths will deliver the same amount of paint over
a different area (wider or narrower strip). A spray
tip with a narrow fan width makes it easy to spray
in tight places. (Thickness of the material coat per
stroke is determined by spray tip fan width, rate of
the spray gun movement, and distance to surface.)
The numbers on the tip identify its orifice size and
fan width. The first number on the tip identifies the
fan width radius in inches. The last two numbers
identify the orifice size in thousandths of an inch.
So, for example, a 517 tip would have a 10 inch fan
width (5 inch radius) and a 0.017 inch orifice size.
SPRAY TIP REPLACEMENT
During use, especially with latex paint, grit and
impurities in the paint under high pressure will
cause the orifice to grow larger from wear and for
the fan pattern width to degrade.
It is easy to determine the state of wear of the tip by
observing the fan pattern. As the tip wears, the fan
width will become narrower. A new tip will have a
A General Guide for Tip Sizes, Flow Rates and Pressures at the Gun ( chart 1)
Material Atomization Pressure (at the gun) Min. RequiredFlow Rate Tip Size Recommended Hose
Lacquer &
semi-transparent stains
1300 PSI(90 BAR) 0.4 gpm(1.5L/min) 0.011" - 0.017"
Oil/alkyd enamels &
0.013" - 0.017"
primers 1/4"
Solid color strains 1500 - 2000 PSI (100 - 140 BAR) 0.4 - 1.0 gpm(1.5 - 3.8L/min) 0.015" - 0.017"
Interior & exterior latex
00015" - 0.025"
paints & primers
Smooth elastomeric
coatings
0.023” – 0.027”
Latex block fillers
2000 - 2500 PSI (140 - 170 BAR ) 1.0 gpm (3.8L/min )
0.025" - 0.030" 3/8"
Elastomeric coatings 0.025" - 0.035"
The atomization pressure is the pressure at the gun, this will always be lower than the pressure at the
pump because the viscosity of the paint, the gun, as well as the length and diameter of the hose will all
cause a pressure drop.
There are many many variables which will effect the spraying pressure such as the temperature and
humidity, the hose, the paint, etc. So, after choosing the right sized tip, the operator must always fine-
tune the pressure to suit the unique conditions of his situation.