Gröne PowerSpray 64, User Manual

Page: 52 / 342

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General guidelines regarding inlet sizes, flow rate and gun pressure.
Material
Atomising pressure
(gun)
Min. required flow
intensity
Inlet size
Recommend-
ed hose
Varnish and translucent
paints
90 bar 1.5 l/min 0.011”-0.017”
1/4”
Oil enamels, alkyds
and primers
100 - 140 bar
140 - 200 bar
170 - 230 bar
1.5 – 3.8 l/min
0.013”-0.017”
Acrylic and indoor emul-
sion paints
0.015”-0.017”
Indoor and outdoor
paints and latex primers
0.0015”-0.025”
Smooth elastomeric
layers
200 - 230 bar
3.8 l/min
4.5 l/min
0.023”-0.027”
3/8” 0.025”-0.030”
Ready-made joint
compounds
0.029”-0.035”
Atomising pressure is the pressure of the gun which is always lower than the pump pressure, be-
cause the viscosity of the paint, the gun and the length and hose diameter contribute to the lowering
of the pressure.
There are many variables which have impact on spraying pressure – temperature, humidity, hose diam-
eter and length, sprayed paint, etc. This is why after choosing the right nozzle size, the operator must
precisely adjust the pressure to the unique conditions in which it operates.
Do not use the nozzle allowing for a bigger flow rate than the pump can handle and bigger than
the sprayer’s efficiency. The flow rate of the liquid passing through the pump is measured in gallons per
minute (GPM) and litres per minute (LPM).
Another parameters describing the inlet is the flow width. Two tips with the same inlet sizes, but with
different flow angle parameters will cover different surfaces with the same amount of paint (wider or
narrower strip). A spraying nozzle with a narrow angle flow facilitates spraying in tight localisation.
(The thickness of covering with a sprayed substance in one stroke is determined by the angle of tip flow,
speed of spraying gun movement and distance between the spraying device and the sprayed surface).
On nozzle tip there are numbers describing the inlet size and flow angle. The first number determines
the flow angle in inches. Two following numbers describe the inlet size in mils. E.g. 517 tip has 25 cm
flow width, (5 (50 degrees) × 5 (constant value) = 25 cm) and inlet size 0.017 inch.
SPRAYING NOZZLE REPLACEMENT
When you use the machine, especially with latex paints, flecks and paint clogging under pressure lead
to expansion of the inlet with work time, and the flow angle will reduce over the time.
The consumption level of the nozzle can be easily assessed by observing the flow angle. Along with
the wear of the tip, the flow angle will decrease. A new tip will cover with its jet a long, thin rectangle
with rounded corners. Over the time of usage the covered element becomes oval.
Entirely used nozzle sprays a round jet. When the flow angle decreases to 2/3 of its primary size,
the nozzle has to be perceived as used.