Burkert Type 8750 - Manual (Page 8)

8
System description
Typ 8750
6. sysTem descripTion
6.1. General description
To determine and control the volumetric flow rate, the pressure drop
over the control valve is measured continuously by the two pressure
sensors. This pressure difference and the valve flow characteristic
are the parameters used to determine the volumetric flow. This mea-
sured volumetric flow is compared with the set point – internally via
display/keyboard or externally via standard signal or bus protocol –
evaluated in a PID controller and set on the position controller as the
new set point.
The system consists of:
• Control valve Type 2712 with process controller Type 8693
• Two pressure sensors Type 8323
Options:
• Binary input
• Analog feedback
• 2 binary outputs
• Bus communication (PROFIBUS DP or DeviceNet)
Other:
• The flow controller is supplied with a factory setting.
• The device is operated via 4 function keys and a display.
• The valve seat can be exchanged.
6.2. structure
Process controller Type 8693
Actuator control valve Type 2712
Signal line from pressure sensor to
the process controller
Valve body control valve
Type 2712
Pressure sensor Type 8323
Flange acc. to
DIN EN 1092-1
Fig. 1: Structure
6.2.1. action diagram of the fmr
Flow
controller
(FMR)
Type
8750
PV
P1 P2
Pressure P1 Pressure P2
Temperature T
(Option)
Kv value
Fig. 2: Action diagram
english