Pneumatics_Unit3_review

The symbol for a directional control valve consists of a separate envelope for each

• port

• flow path

• direction

• position

A directional control valve with two flow path configurations and three fluid ports is called a

• 3-port, 2-position directional control valve.

• 2-port, 3-position directional control valve.

• 2-port, 2-position directional control valve.

• 3-port, 3-position directional control valve.

They are commonly used to control the speed of fluid actuators

• Directional control valves

• Check valves

• Flow control valves

• Shutoff valves

They are commonly used to control the direction of fluid actuators.

• Check valves

• Directional control valves

• Flow control valves

• Shutoff valves

When the actuator does not work against a constant load,

• the meter-in configuration is commonly used to control the speed.

• the meter-in and meter-out configurations are commonly used to control the speed

• the meter-out configuration is commonly used to control the speed.

• neither the meter-in nor the meter-out configurations are commonly used to control the speed

Which of the following statements is false?

• The actuator speed is more stable with a meter-out configuration in comparison to a meter-in configuration.

• The meter-out configuration is frequently used with double-acting cylinders

• The meter-in configuration controls the flow exhausting an actuator.

• The meter-in configuration is frequently used with single-acting cylinders

The housings and spools of pilot-operated valves

• are similar to those of direct-operated valves

• are different from those of direct-operated valves

• are smaller than those of direct-operated valves

• are bigger than those of direct-operated valves.

Pilot-operated valves may move their spools using

• a pedal

• a pushbutton

• one or two pilots along with a return spring

• a lever.

Pilot-operated valves reduce the delays caused by

• complex circuits.

• compressibility of air and friction in long tubing lines

• components connected in series.

• high-pressure pilot lines.

A double-pilot 5-port, 2-position directional control valve

• does not have exhaust ports

• has one exhaust port by flow-path configuration.

• has two exhaust ports by flow-path configuration.

• has three exhaust ports by flow-path configuration