Recipe
Recipe
Recipe Screen
Screen
Screen 3
3
3
Figure 53 Recipe Screen 3
Mix
Mix
Mix Pressure
Pressure
Pressure Tolerance
Tolerance
Tolerance
The pressure of one component must be within a
percentage of the pressure of the driving component
during spray or mix. Set the desired Mix Pressure
Tolerance in these fields for the relationship between
each component and the drive component. The
component relationship labels are determined based
on the components used with the recipe and the
Drive Pump set on Recipe Screen 1. The labels
indicate the reference (drive component) on the right
of the colon. The default set point value is 25%.
See
Differential Pressure and the Mix Pressure
.
Differential
Differential
Differential Pressure
Pressure
Pressure and
and
and the
the
the Mix
Mix
Mix Pressure
Pressure
Pressure
Tolerance
Tolerance
Tolerance Set
Set
Set Point
Point
Point
A primary means of maintaining ratio assurance for
the ProMix PD3K+ system is through monitoring
of the differential pressure between the drive
component-pump and the other component-pump
outlets. Ideally, these pressures would be identical,
but factors such as line sizing, viscosity, and mix
ratio lead to some variation. Understanding where
your system typically operates is imperative when
setting up an effective differential pressure check that
notifies the user of potential mix ratio inaccuracies
while avoiding nuisance alarms.
It is recommended that, once the system is fully
installed and ready to use, the user load a recipe and
then spray the mixed material. While spraying, note
the outlet pressures of all component pumps (per
the ADM’s main screen or the PLC) and spray long
enough to ensure the pressures have stabilized to
a nominal value. The difference between the outlet
pressures of the drive pump and other component
pumps is an established baseline for the Mix
Pressure Tolerance set point.
The Mix Pressure Tolerance set point allows the
other component pump outlet pressure to vary a
specified percentage away from the drive pump
outlet (spray) pressure. For example: In the following
figure, if the spray pressure (A-side pump outlet
pressure) is 100 psi, and the Mix Pressure Tolerance
is set to 25%, the B-side outlet pressure is allowed to
float between 75 and 125 psi (100 psi ± 25%) without
generating an alarm.
0
20
40
60
80
B
100
A
120
140
Figure 54 The acceptable B-side pump outlet
pressure range for a system with a target spray
pressure (A) of 100 psi and a Mix Pressure Tolerance
of 25%.
It is recommended that you keep the Mix Pressure
Tolerance set point as low as possible to alert the
user of anything affecting the mix ratio accuracy.
However, if your system is generating several
differential pressure alarms, or will be mixing a wide
variety of materials at different mix ratios, you may
need to increase the Mix Pressure Tolerance.
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