Controls - Part A

Question 1

(T/F) A controlled system is made up of all the equipment in which the controlled variable exists. This includes all of the automatic control equipment.

Answer 1

False

Question 2

(T/F) An example of a direct means of measurement is using a pressure gauge to calculate the height of liquid in a vessel.

Answer 2

False

Question 3

(T/F) An example of a primary element is the float in a low water cut-off that senses the height of the boiler water in a steam boiler.

Answer 3

True

Question 4

(T/F) A closed loop system gives feedback on the isolated controlled area back to the controller.

Answer 4

True

Question 5

(T/F) In a cascade system, there is generally a (major) inner loop and a (minor) outer loop.

Answer 5

False

Question 6

What is a pneumatic operator?

Answer 6

A pressure actuated device

Question 7

What are two (2) types of pneumatic operators?

Answer 7

A) dampers
B) valves

Question 8

Normally open = Failsafe _______

Answer 8

Open

Question 9

Normally closed = Failsafe _______

Answer 9

Closed

Question 10

In a parallel operation, the spring ranges for the final operators are the same. This means that more than one operator will open and close _________.

Answer 10

Together

Question 11

On a direct acting controller, when the temperature increases, the pressure on the outpost signal _________.

Answer 11

Increases

Question 12

On a reverse acting controller, when the temperature decreases, the pressure on the outpost signal __________.

Answer 12

Increases

Question 13

The type of controller that can continually exhaust branch-line control air is a ________ ________.

Answer 13

Bleed type

Question 14

When moving a dial on a thermostat to 21°C (70°F), you are adjusting the ______ _______.

Answer 14

Set point

Question 15

(T/F) An auxiliary device is usually found between the controller and the final element.

Answer 15

True

Question 16

(T/F) An electric to pneumatic relay converts a pneumatic signal to an electric signal.

Answer 16

False

Question 17

(T/F) A bias start relay is used to sequence overlapping spring ranges on the final elements.

Answer 17

True

Question 18

(T/F) A positive-positioner is used in a control valve operator to increase the stroking speed.

Answer 18

False

Question 19

One of the primary importance of instrumentation is:

Answer 19

Pressure

Question 20

A device that will give a direct measurement is a:

Answer 20

Gauge glass

Question 21

An example of a type of indicator is a:

Answer 21

Bimetal strip

Question 22

Using a direct acting controller and a normally closed valve; as the temperature rises, the NC valve will:

Answer 22

Open

Question 23

The maximum pressure setting on an instrument air main is:

Answer 23

25psi

Question 24

The type of controller that exhausts from the branch-line only while reducing the branch-line pressure is:

Answer 24

Non-bleed type

Question 25

Two position controllers are also called:

Answer 25

Positive-acting

Question 26

A volume booster is used on a:

Answer 26

Final element

Question 27

In cold freezing conditions that are affecting a heating coil, the primary function of a freeze-stat is to:

Answer 27

Shut down fans

Question 28

The type of element that is normally used as a freeze-stat is:

Answer 28

Averaging sensor