Graco EcoQuip 300 Operation, Repair, And Parts page 16

Operation
Metering Valve Valve Settings Settings
Metering Metering Valve Settings
There is no fixed formula for what works best in each application. The information below works best for the
majority of the time. From this initial setting, adjustments can be made up or down to get the fastest removal
rates without damage to the surface.
Normal settings are: 110 psi (7.5 Bar, 0.75 MPa) initial pot setting, less than 1/2 turn open metering valve,
blasting pressure at 80 psi (5.5 Bar, 0.55 MPa). For applications requiring higher performance, use
high-performance abrasive (the heaviest mass @ 80 grit) such as Garnet, and the highest pressures the
compressor can support. The initial pot pressure should always be 30 psi (2.0 Bar, 0.2 MPa) above the
intended blast pressure.
Gradually make adjustments to meet the specific requirements for each application. Higher blast pressures
will require turning the abrasive metering valve slightly more open (and vice versa). Make the adjustments
(see DataTrak Controls, page 7
rate while using the least amount of abrasive). Blasting pressures can range between 30 - 120 psi max
(2.0 Bar, 0.2 MPa – 8.2 Bar, 0.82 MPa).
Unlike conventional sandblasting, higher pressures do not necessarily mean better cleaning. Nozzle distance
and the angle to the surface has an effect on performance, as does the blast pressure. Choice of abrasive
also has a great effect. High-performance abrasive produces the best performance and can save enough
time to make up the difference in cost.
NOTE: Blasting with 150+ feet of blast hose requires the use of an electric blast control.
NOTE: NOTE:
Grit Size Size
Grit Grit Size
General
General General 40/70
Wood
Wood Wood 80 (using a low
mass abrasive
like glass)
Steel
Steel Steel 80-100 (using
a high-mass
abrasive like
Garnet)
Fiberglass
Fiberglass Fiberglass 40-70 low mass
16
) to achieve 7-10 cycles per minute to be the most efficient (cut at the fastest
Blast Blast Pressure Blast Pressure Pressure Abrasive Abrasive Dose Abrasive
60-80 psi (4.1 Bar, 1/4 to 1/2 turns
0.41 MPa- 5.5 Bar,
0.55 MPa)
40-50 psi (2.7 Bar, 1/8 to 1/4 turns
0.27 MPa- 3.4 Bar,
0.34 MPa)
1/4 – 1/2 turns
100-120 psi (6.8 Bar,
0.68 MPa- 8.2 Bar,
0.82 MPa)
45-65 psi (3.1 Bar, 1/8 to 1/4 turns
0.31 MPa- 4.4 Bar,
0.44 MPa)
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Dose Dose Blast Blast Angle Blast Angle Angle
35° - 65° When the blast
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
15° - 30° Do not wash, as it
may raise the wood
grain. Brush off
excess abrasive after
the wood dries.
When the blast
65° - 85˚
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
35° - 45˚ When the blast
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
Notes Notes Notes
334667B