9 | GE Oil & Gas
© 2016 General Electric Company. All rights reserved.
Conversion to VRP-SB-PD Controller:
For highly unstable systems it may be necessary to convert the VRP-SB-PID into a VRP-SB-PD controller. In this case the controller will
have a permanent offset due to an absence of the integral function.
Figure 4 - Direct Acting VRP-SB-PID Controller
Figure 5 - Reverse Acting VRP-SB-PID Controller
Power
Gas
Exhaust
Vent
Output
Output
Integral
(Full Closed)
Integral
(Full Closed)
Derivative
Output
Block Valve
Sensing
Pressure
Sensing
Pressure
Vent replaces
the plug
Derivative
Output
Block Valve
Feedback
Module
Power gas is fed
into the integral
chamber
P4
1
P
2
P
P3
P1
P3
P4
P2