PIC Quiz (Chap l control valves Tutorial 12 Part A)

Which part of the actuator senses the input pressure from the controller and convert to movement of the stem?

• Plug.
• Body.
• Spring.
• Diaphragm.

The part that allows the valve stem to move up and down with minimal leakage of the process fluid is

• plug.
• stem.
• seat ring.
• packing box.

The components of the control valve that are in contact with the process fluid is the

• stem.
• trim.
• spring.
• actuator.

The valve stem in the control valve is used to

• allow fluid to flow through.
• transmit movement to the plug.
• convert electronic signal to pneumatic signal.
• sense air pressure and convert it into mechanical movement.

The diaphragm in the control valve is used to

• allow fluid to flow through.
• transmit movement to the plug.
• convert electronic signal to pneumatic signal.
• sense air pressure and convert it into mechanical movement.

What regulates the supply of material to a process by adjusting an opening through which the material flows?

• Recorder.
• Controller.
• Transmitter.
• Control valve.

For a direct-acting valve, upon air failure it will

• Close fully.
• Open fully.
• Sound an alarm.
• Remain at its position.

Which ONE of the following process fluid is suitable for Fail-Open control valve?

• Steam.
• Heating oil.
• Cooling water.
• Concentrated acid.

The Fail-Close valve is used for

• Stack gas.
• Fire water.
• Cooling water.
• Instrument air.

A control valve is used to regulate steam flow to a process and the high temperature input can trigger explosive reaction. What action of the control valve must be utilized to achieve a failsafe operation?

• Air to open.
• Air to close.
• 3 psi to open.
• 15 psi to close.