CPT CPT Fluid Systems & Hydraulics 2

Question 1

In a hydraulic system, what does a directional control valve control?

Accepted Answer

The path fluid takes through the circuit

Answer

A directional control valve routes hydraulic fluid to different actuator ports, controlling the direction of cylinder or motor movement.

Question 2

Which hydraulic fluid property most affects the performance of a system at low temperatures?

Accepted Answer

Viscosity

Answer

Viscosity increases significantly at low temperatures, reducing pump efficiency and increasing pressure drop across lines and valves.

Question 3

A hydraulic cylinder has a bore diameter of 4 inches and a rod diameter of 2 inches. Which side produces more force at equal pressure?

Accepted Answer

Bore (cap) side

Answer

The cap (bore) side has a larger effective area since no rod occupies it, so at equal pressure it produces more force than the rod side.

Question 4

What is the primary reason for using a hydraulic filter with a bypass indicator?

Accepted Answer

To alert the technician when the filter element is clogged and fluid is bypassing filtration

Answer

When the filter element clogs, a bypass valve opens to maintain flow; the bypass indicator (pop-up or gauge) signals that the element needs replacement before contamination damages components.

Question 5

Aeration in hydraulic fluid appears as which symptom during system operation?

Accepted Answer

Foamy or milky fluid with spongy actuator response

Answer

Entrained air creates foam and causes erratic, spongy actuator movement because air is compressible unlike hydraulic fluid.

(CPT) Certified Process Technician Practice Test

(CPT) Certified Process Technician Practice Test

CPT CPT Fluid Systems & Hydraulics 2