Control & Instrumentation Flashcards
Foundation Layers Instrumentation
- Base Layer Control
- Intermediate Layer Control
- Advanced Regulatory Control
- Advanced Process Control
Process Instrumentation
all measuring instruments and final
control elements typically found in the Hydrocarbon processing industry with the exclusion of quality measurements
Primary
Typical Process Parameters
- Pressure
- Temperature
- Level
- Flow
Pressure Instruments
- Gauges
- Pressure switches
- Transmitting devices
Signal Converters
measures a physical value and convert it into a standardized signal
Duty of a signal converter
to convert an analog signal into a different one, adapting it to control inputs/outputs or allowing for long-distance signal transmission without interference
Other reasons for using converters
- Signal amplification
- Galvanic isolation (optical/magnetically)
- Signal protection against environmental influences.
- Avoiding destruction by ground loops.
Pressure Transmitters
designed to measure fluid pressure and transmit that information via electrical signals
Transmitters used in PETRONAS
MLNG-Satu - Rosemount 3051
MLNG-Dua - Foxboro I/A
ABF - Yokogawa DP Harp
PP(M)SB - Rosemount
Types
Level Measurements
- Direct
- Indirect
three major sub-assemblies
Control valve
- Valve body
- Valve actuator
- Valve positioner
Issues for Control:
Valve Body
i) Packing tightness
ii) Foreign material in packing.
iii) Plug/seat sticking
iv) Sizing issues
Issues for Control:
Actuator - Diaphragm
i) Diaphragm leak
ii) Actuator housing leaks
iii) Vent blockages
Issues for Control:
Actuator - Piston
i) Piston Seal leak
ii) Actuator housing leaks
iii) Vent blockages
