NCED Hydraulic & Pneumatic Systems 3

Question 1

Which component in a pneumatic system removes moisture from compressed air before it enters the distribution lines?

Accepted Answer

Air dryer

Answer

An air dryer (refrigerated or desiccant type) removes water vapor from compressed air to prevent corrosion and valve damage downstream.

Question 2

What is the typical operating pressure range for most industrial pneumatic systems?

Accepted Answer

80–120 psi

Answer

Industrial pneumatic systems commonly operate between 80 and 120 psi, which is sufficient for most actuator and tooling applications.

Question 3

A 4/2 directional control valve designation means the valve has:

Accepted Answer

4 ports and 2 positions

Answer

Valve nomenclature lists ports first and positions second, so a 4/2 valve has 4 ports and 2 switching positions.

Question 4

What does a flow control valve with a check valve bypass (meter-out configuration) control?

Accepted Answer

The exhaust flow rate from the actuator

Answer

A meter-out flow control restricts the exhaust flow leaving the actuator, controlling speed while maintaining back-pressure for load stability.

Question 5

In a pneumatic FRL unit, what does the 'L' stand for?

Accepted Answer

Lubricator

Answer

FRL stands for Filter-Regulator-Lubricator, the three conditioning components typically installed together at pneumatic system entry points.

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