A valve actuator

A valve actuator

a) cannot be reverse acting
b) will always have one side of the diaphragm open to atmosphere
c) is a two-position device
d) position is a function of controller output
e) causes a valve to always fail open




Answer: D

When a recorder receives a signal from a transmitter, the recorder incorporates a

When a recorder receives a signal from a transmitter, the recorder incorporates a

a) signal reverser
b) pneumatic relay
c) flapper-nozzle assembly
d) capsule or bellows
e) transducer




Answer: D

A proportional only controller

A proportional only controller

a) cannot maintain maximum value of the final element
b) cannot maintain set point except at 50%
c) can be compared to the cruise control on an automobile
d) will maintain measured variable at set point
e) will respond fully when deviation is high




Answer: B

The output pressure signal of a transmitter relay is usually

The output pressure signal of a transmitter relay is usually

a) direct and proportional to nozzle pressure
b) a function of supply pressure
c) inversely proportional to nozzle pressure
d) fed to a final element of a loop
e) the same as the primary element output signal





Answer: A

A flapper-nozzle assembly is basic to all

A flapper-nozzle assembly is basic to all

a) controllers
b) transmitters
c) recorders
d) pneumatic devices
e) actuators





Answer: B

On a basic pneumatic transmitter, a movement of the flapper towards nozzle will:

On a basic pneumatic transmitter, a movement of the flapper towards nozzle will:

a. Increase the nozzle bleed.
b. Change the size of the supply orifice.
c. Maintain steady transmitter output.
d. Change transmitter supply pressure.
e. Increase feedback bellows pressure.





Answer: E

Putting a controller on manual control means:

Putting a controller on manual control means: 

a. The operator controls the final control element.
b. The controller output responds to a process variable.
c. There is no control of the final control element.
d. The operator manually adjusts the process by changing the process variable signal
e. The automatic controls have failed.

Answer: A

A valve which gives good throttling action, takes less actuator force, but does not seal well is a:

A valve which gives good throttling action, takes less actuator force, but does not seal well is a:

a. Double seated valve
b. Reverse acting valve
c. Multiple-disc valve
d. Single seated valve
e. Direct acting valve





Answer: A

A proportional-only controller:

A proportional-only controller:

a. Are mostly used for on/off control.
b. Compare actual conditions to controller outputs.
c. Must provide reset action.
d. Cannot always maintain the process variable exactly at the set-point.
e. Are sometimes called Multi-position controllers



Answer: D

Most solenoid valves operate so that the upstream line pressure will:

Most solenoid valves operate so that the upstream line pressure will:

a. Act to open the valve
b. Be less than downstream pressure
c. Be sensed by a transmitter
d. Act to close the valve
e. Must pass through a restriction or nozzle





Answer: D

Cascade control utilizes:

Cascade control utilizes:

a. One controller, one transmitter and two valves.
b. One controller, two transmitters and two valves
c. Two controllers, one transmitter and two valves.
d. Two controllers, two transmitters and two valves.
e. Two controllers, two transmitters and one valve.





Answer: E

A circular chart recorder:

A circular chart recorder:

a. Provides a different function than a strip chart.
b. Is newer design than a strip chart.
c. May incorporate a bourdon tube.
d. Does not provide a permanent record.
e. Is used on a computer screen.




Answer: C

A sensing element sends its signal to

A sensing element sends its signal to

a. a Transmitter
b. an air line
c. a Conveyer
d. a Flapper and nozzle
e. a Recorder




Answer: A

A CRT or LCD display trend recorder

A CRT or LCD display trend recorder

a. Often has a number of dedicated displays
b. Is equipped with graph limiters
c. Does not have print out capabilities
d. Displays only a single trend at a time
e. Is independent of the transmitter signal





Answer: A

A CRT trend display:

A CRT trend display:

a. Mimics a trend chart.
b. Is dedicated to a single process.
c. Is limited to displaying a fixed or nonadjustable time period.
d. Allows a view of only one process variable at a time.
e. Is normally mounted beside the final control element.

Answer: A

A pneumatically actuated control valve which opens on air failure has a:

A pneumatically actuated control valve which opens on air failure has a:

a. Direct acting actuator and direct acting valve.
b. Direct acting actuator and reverse acting valve.
c. Reverse acting actuator and direct acting valve.
d. Is typically used for a burner firing rate control valve
e. Is typically used for a feedwater control valve





Answer: A

A recorder utilizing a spiral Bourdon tube will have a pen movement:

A recorder utilizing a spiral Bourdon tube will have a pen movement:

a. On a logarithmic scale
b. Proportional to the change in tube pressure
c. That is often imperceptible
d. Range of 0 to 24 hours
e. Range of 0 to 7 days





Answer: B

Normally-closed solenoid operated valves open when

Normally-closed solenoid operated valves open when

a. a coil is electrically energized
b. pressure below the valve disc overcomes the spring pressure above the disc
c. a pneumatic signal exceeds 20 kPa
d. an electric motor opens the valve
e. it is de-energized





Answer: A

In a pneumatic control system, the nozzle receives a regulated air supply pressure of approximately:

In a pneumatic control system, the nozzle receives a regulated air supply pressure of approximately:

a. 140 psi
b. 20 kPa
c. 140 kPa
d. 210 kPa
e. 30 kPa




Answer: C

A control valve that has one plug that moves upward to close the port is called:

A control valve that has one plug that moves upward to close the port is called:

a. Reverse acting single ported.
b. Double seated direct acting.
c. Reverse acting diaphragm actuated.
d. Direct acting single ported.
e. A solenoid





Answer: A