Setting The Abrasive Metering Valve; Valve - Graco EcoQuip2 EQm Operation, Repair, And Parts

Operation
Setting the the Abrasive Abrasive Metering
Setting Setting the Abrasive
The optimal set point of the abrasive metering valve
and corresponding MediaTrak CPM value varies
significantly depending on application and user
desired performance. The General
Guides Guides on the next page describe the generally Guides
accepted range of CPM set points based on the
substrate and blast pressure set point. The grey
highlighted area illustrates the typical range of blast
pressure set points and their corresponding CPM set
points for that substrate.
To find the recommended CPM set point, select the
table that most closely matches the substrate that
is to be blasted. Determine the blast pressure set
point based on the media that is being used, and the
desired surface profile to be achieved. Then, use
the corresponding lines on the chart to select the
appropriate CPM set point.
For inexperienced users, select a blast pressure
near the low end of the highlighted range. Increase
blast pressure and CPM until the desired profile and
removal rate are achieved.
16
Metering Valve

Valve

Metering Valve
General Application General Application Application
Optimizing the the Abrasive Abrasive Metering
Optimizing Optimizing the Abrasive
Valve
Valve Valve
To optimize performance, use the High Production or
Media Efficient lines on the charts. CPM set points
near the High Production lines will yield the highest
removal rates, and the highest media consumption
rates. To maximize removal rate regardless of media
consumption, use the highest possible blast pressure
and set the CPM to the highest achievable value that
produces a consistent pattern. The CPM set point is
too high if the flow from the nozzle starts to sputter.
CPM set points near the Media Efficient line will use
the lowest amount of media. To minimize cleanup
and media usage, use a set point closer to this line.
Generally, removal rates will be less than average
when setting the CPM according to this line.
The charts on the following page are only guidelines.
They were developed using garnet media in the
30-80 mesh range. Coarser media will produce a
deeper profile, but will require higher CPM set points
to yield similar removal rates to the set points shown
in the tables. Finer media will yield higher removal
rates, but will not produce as deep of a profile.
Fine tuning and experimentation are necessary to
optimize performance for each application.
General Application General General Application Guides Application
See See the See the the
page. page. page.
Metering
Metering
Guides Guides
on the on on the following the following following
3A3489A