
Installation, Operating & Maintenance Instructions
Series 615 DN 40 (I.D. 1.5”), RS485
VAT Vakuumventile AG, CH-9469 Haag, Switzerland
Tel +41 81 771 61 61 Fax +41 81 771 48 30 [email protected] www.vatvalve.com
289111EB
2013-02-05
35/96
3.6.6.3
Soft pump
This valve may be used for downstream control depending on configuration. The P parameters of the pressure controller
require correct adjustment. These parameters must be set once during system setup and are stored in the device memory
which is power fail save. Based on the P controller configuration, the valve is able to run fast and accurate pressure
control cycles. The P parameters can be calculated approximately with the formulas below. On request VAT can provide a
parameter calculation tool .
Note:
In
downstream
control mode valve will move towards open when current pressure is higher then setpoint.
P-Gain
Step 1 (choose the applicable formula depending on units you are familiar with):
d V p
SFS
K =
q
max
1.737 10
6
d
Valve
diameter [
mm
]
V
Chamber
volume [
l
]
p
SFS
Sensor
full scale
1)
[
Pa
]
q
max
max.
gasflow
to control [
Pa m
3
/s
]
d V p
SFS
K =
q
max
1.737 10
3
d
Valve
diameter [
mm
]
V
Chamber
volume [
l
]
p
SFS
Sensor
full scale
1)
[
mbar
]
q
max
max.
gasflow
to control [
mbar l/s
]
d V p
SFS
1.151
K =
q
max
d
Valve
diameter [
inch
]
V
Chamber
volume [
l
]
p
SFS
Sensor
full scale
1)
[
Torr
]
q
max
max.
gasflow
to control [
sccm
]
2)
In case of 2 sensor operation use high range sensor for calculation (615 . . - . . .
Q
- . . . . version only)
Step 2:
P-Gain = K (but max. 10)
K
Gain
3.7 Close valve
Local operation
:
(„Control View‟, „Control Performance Analyzer‟ or
„Service Box 2„)
Remote operation
:
(Refer to chapter «RS485 control commands» for
details)
Push CLOSE button
Send CLOSE VALVE
3.8 Open valve
Local operation
:
(„Control View‟, „Control Performance Analyzer‟ or
„Service Box 2„)
Remote operation
:
(Refer to chapter «RS485 control commands» for
details)
Push OPEN button
Send OPEN VALVE