![background image](http://html1.mh-extra.com/html/graco/234129/234129_instructions-manual_2251484035.webp)
Configuring Software
309738L
35
Flow Rate Calibration
The system only calibrates flow rate if you are operating
in Bead Control Mode. Flow rate calibration takes place
immediately after the pressure calibration in bead con-
trol mode.
How Flow Rate Calibration Works
Each application may have different flow rate require-
ments. Flow rate calibration verifies the maximum flow
rate of the system and determines the regulator outlet
pressure required to achieve the required flow rate.
At the start of the flow rate calibration procedure, you
need to enter the maximum flow rate required by the
application. When you actuate the dispensing device
during calibration, the control unit:
1.
Measures the maximum system flow rate. If the
maximum system flow rate is less than the required
maximum flow rate a fault is generated.
2.
Determines the outlet pressure required to obtain
the flow rate value you entered.
3.
Calculates a linear ratio of the automation analog
input voltage to the desired flow rate. Refer to F
Flow Rate Guide
Use the values in
Table 5 - Maximum Flow Rate Val-
as a guide to determine the maximum flow
rate to enter during flow rate calibration.
Table 5 - Maximum Flow Rate Values (cc/min)
Setting Inlet Pressure
The inlet pressure reading should be in the range of 300
psi (2.1 MPa, 21 bar) to 500 psi (3.4 MPa, 34 bar) above
the outlet pressure reading under your highest flow con-
dition.
Excessive inlet pressure will cause accelerated wear on
the regulating valve and the pump feed system.
Feed System Pressure Drop
During material flow, the regulator inlet pressure
decreases. The amount the pressure decreases is the
amount of pressure lost between the feed pump and the
regulator inlet. With high viscosity fluids, long line
lengths, or small diameter line sizes this pressure
decrease can be thousands of psi (hundreds of bar).
This means that the static pump pressure is set much
higher than the regulator needs at its inlet. To prevent
excessive control regulator wear or surging, a mastic
fluid pressure regulator is recommended on the feed line
close to the control regulator. The mastic regulator will
suppress the static feed pressure at the control regulator
inlet.
F
IG
. 17
Flow mode: Analog voltage to flow rate ratio
Max.
Flow
Rate
Flow Rate
(cc/minute)
0
0
10
Automation Flow Command
Volts (Vdc)
Round Equivalent Bead Diameter (mm)
Max. Automa-
tion Speed
(mm/sec)
2
3
5
7
9
50
10
21
59
115
191
100
19
42
118
231
382
200
38
85
236
462
763
300
57
127
353
693
1145
400
75
170
471
924
1527
500
94
212
589
1155
1909
600
113
254
707
1385
2290
700
132
297
825
1616
2672
800
151
340
943
1847
3054
900
170
382
160
2078
3435
1000
189
424
1178
2309
3817