AME 11 End of Unit – SVE Study

AME 11 End of Unit Quiz

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What happens when the flow out is increased in a system where the water tank level is controlled by a float and lever proportional system?

C) The float rises, causing the control valve to close, reducing the inflow.

A) The float rises, causing the control valve to open more to increase the inflow.

D) The float drops, causing the control valve to open more to increase the inflow.

B) The float drops, causing the control valve to close, reducing the inflow.

2 / 12

What is the primary characteristic of a Discontinuous (On-Off) control system?

D) The system provides proportional control based on the error magnitude.

C) The system adjusts output in small increments.

A) The output is continuously variable.

B) The output is either fully on or fully off, with no intermediate states.

3 / 12

Explain derivative action in control terms.

D) Derivative action is the component of the control system that maintains the steady-state error by constantly adjusting the control output proportionally.

A) Derivative action involves adjusting the control output based on the rate of change of the error, aiming to predict future errors and reduce overshoot.

C) Derivative action adjusts the control output based on the proportional deviation from the setpoint, with no regard to the rate of change.

B) Derivative action describes the process of integrating the accumulated error over time to adjust the control output.

4 / 12

Describe the reasons for integrating the error signal and the effect it has on the governor fuel rack.

A) Integrating the error signal helps in eliminating steady-state error by providing continuous correction over time, leading to a gradual adjustment of the governor fuel rack to maintain the desired engine speed.

C) Integrating the error signal helps in reducing the proportional gain needed for control, which simplifies the control system and makes the governor fuel rack less responsive to changes in engine speed.

B) Integrating the error signal helps in amplifying transient responses by applying a large correction immediately, causing abrupt changes to the governor fuel rack and quickly adjusting the engine speed.

D) Integrating the error signal helps in stabilizing the system by making the governor fuel rack adjustments slower, which prevents any rapid changes and ensures the engine speed remains constant.

5 / 12

State with reasons, the type of actuator fitted to the process valves for a lubrication oil cooling system in which the valve diverts the oil through a cooler.

B) Pneumatic Actuator: Reason: Pneumatic actuators provide reliable and fast operation and are well-suited for applications requiring frequent adjustments to the valve position, such as diverting oil flow through a cooler.

C) Hydraulic Actuator: Reason: Hydraulic actuators are generally used for high-force applications and may be less suitable for the precise control required in diverting oil through a cooler.

A) Electric Actuator: Reason: An electric actuator offers precise control of the valve position and can be easily integrated with control systems to modulate the oil flow through the cooler as required.

D) Manual Actuator: Reason: Manual actuators require manual intervention to adjust the valve position, which is not ideal for automatic and precise control of oil flow through a cooler.

6 / 12

State the reasons for fitting a pneumatic process valve with a feedback positioner.

B) A feedback positioner is fitted to increase the air pressure supplied to the actuator, which helps in enhancing the overall force applied to the valve.

A) A feedback positioner is fitted to monitor the valve position and provide real-time correction signals to ensure the valve remains at the desired position, improving accuracy and stability in the process control.

C) A feedback positioner is fitted to reduce the overall power consumption of the valve actuator, improving energy efficiency.

D) A feedback positioner is fitted to provide a backup control signal in case the primary control system fails, ensuring the valve remains operational.

7 / 12

State the reasons for fitting a pneumatic process valve with a volume booster.

A) A volume booster is fitted to increase the flow rate of air to the actuator, enabling faster valve movement and reducing the time required to achieve the desired valve position.

C) A volume booster is fitted to decrease the overall air consumption of the valve, thereby improving energy efficiency in the pneumatic system.

B) A volume booster is fitted to reduce the air pressure supplied to the actuator, which helps in minimizing the force required to operate the valve.

D) A volume booster is fitted to provide redundant control signals to the actuator, ensuring higher reliability in case of signal loss.

8 / 12

State with reasons, the type of actuator fitted to the process valves for a fuel supply system in which the valve must not move on loss of power to the control system.

B) Pneumatic Actuator with Spring Return: Reason: This actuator is designed to return to a default position using a spring when power is lost, which could result in undesired movement or system instability.

C) Hydraulic Actuator with Manual Override: Reason: While this actuator allows for manual control, it is not ideal for maintaining valve position during power loss, as it may require manual intervention to secure the valve.

D) Solenoid Actuator: Reason: This actuator is not suitable as it relies on continuous power to maintain the valve position and will fail to hold the valve in place if power is lost.

A) Electric Actuator with Fail-Safe Mechanism: Reason: This actuator includes a fail-safe mechanism that ensures the valve remains in its last position or moves to a predetermined safe position if there is a loss of power.

9 / 12

With reference to engine governors, explain sensitivity.

B) Sensitivity refers to the governor’s response to small changes in the fuel supply, affecting the engine speed control. Reason: A sensitive governor will react quickly to minor adjustments in fuel input, thereby maintaining precise engine speed control.

C) Sensitivity describes how easily the governor can detect changes in ambient temperature and adjust engine speed accordingly. Reason: While temperature changes can affect engine performance, sensitivity in a governor is primarily related to its response to load changes and fuel adjustments.

A) Sensitivity refers to the governor's ability to maintain engine speed despite fluctuations in load conditions. Reason: A sensitive governor adjusts engine fuel input or throttle position to counteract variations in load and keep the engine speed constant.

D) Sensitivity indicates the level of noise produced by the governor during operation. Reason: Noise levels are not related to the sensitivity of a governor but rather to its design and operation characteristics.

10 / 12

Define the term Proportional Action.

C) Proportional action predicts future errors by adjusting the control output based on the rate of change of the error.

D) Proportional action uses a fixed output level regardless of the error magnitude to maintain system stability.

A) Proportional action adjusts the control output based on the magnitude of the error, where the output is directly proportional to the difference between the setpoint and the actual value.

B) Proportional action integrates the error over time to adjust the control output, aiming to eliminate steady-state error.

11 / 12

Describe the effect of increasing the controller gain with respect to the steady-state tank level when the outflow is increased in a float and lever proportional system.

D) The steady-state tank level will remain unchanged regardless of the controller gain.

A) The steady-state tank level will become more stable and closer to the setpoint.

C) The steady-state tank level will decrease more slowly in response to the increased outflow.

B) The steady-state tank level will oscillate more and be less stable.

12 / 12

What is the relationship between proportional band and gain in a control system?

D) Proportional band and gain are the same thing.

A) Proportional band is directly proportional to gain.

B) Proportional band is inversely proportional to gain.

C) Proportional band and gain are independent of each other.

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