IAMI Control Flashcards
Describe, with the aid of a sketch, a method of remotely monitoring the contents of a fuel tank
INSERT SKETCH
1), a Hemispherical ball is fitted near the bottom of the tank and connected by small bore pipping to a mercury manometer.
2), a Selector Cock allows one manometer to monitor multiple tanks.
3), a Three Way Cock is used to select between air, gauge and vent positions.
- at “air” compressed air fills the system.
- at “gauge” the air pressure balances against the liquid head, causing a reading on the manometer.
4), This reading corresponds to the tanks liquid level.
- After reading, the cock is turned to “vent” to release the pressure.
Describe, with the aid of a sketch, a method of remotely monitoring the contents of a fuel tank
INSERT SKETCH
1), a Hemispherical ball is fitted near the bottom of the tank and connected by small bore pipping to a mercury manometer.
2), a Selector Cock allows one manometer to monitor multiple tanks.
3), a Three Way Cock is used to select between air, gauge and vent positions.
- at “air” compressed air fills the system.
- at “gauge” the air pressure balances against the liquid head, causing a reading on the manometer.
4), This reading corresponds to the tanks liquid level.
- After reading, the cock is turned to “vent” to release the pressure.
with reference to control systems
List FOUR examples of a measured variable
- Pressure
- Temperature
- Flow
- Power
- Time
- Level
- Speed
- Torque
Explain the meaning of the term two step control, giving one example of its use
Two-step Control means a system has 2 fixed actions based on reaching certain points, usually ON and OFF or Start and STOP.
EXAMPLE
In a boiler feed system, a high water level will stop the feed pump, and a low water level will start the feed pump. (nothing gradual, just swaps between 2 states)
Explain the meaning of the term proportional control, giving one example of its use
Proportional Control means the control output changes in proportion to the difference (error) between the measured value and the set point.
It helps maintain smooth and stable operation with minimal error.
EXAMPLE
If the engine cooling water temperature set point is 85°C but the actual temperature rises to 90°C, the proportional controller will open the cooler valve more to bring the temperature back down gradually.
Describe with the aid of a sketch, a typical single element temperature control of a large lubricating oil system
INSERT SKETCH
Single element temperature control means only one variable is being measured and controlled.
In this case the oil temperature.
1), L.O is pumped from the sump through course and fine filters
2), Temperature sensor measures oil temperature.
3), Signal sent to controller for comparison with set point.
4), Controller adjusts 3 way valve position.
- if oil is hot, more oil passes through the cooler.
- if temperature is cold, oil bypasses the cooler.
5), Conditioned oil is sent to the engine.
6), Continuous feedback maintains correct temperature.
