433A Hydraulic Systems

Question 1

What is Pascal's Law as it applies to hydraulic systems?

Accepted Answer

Pressure applied to a confined fluid is transmitted equally in all directions throughout the fluid

Answer

Pascal's Law states that pressure applied to a confined fluid is transmitted undiminished and equally in all directions throughout the fluid and acts on every surface in contact with the fluid.

Question 2

What is the function of a hydraulic relief valve?

Accepted Answer

To protect the system from excessive pressure by diverting flow back to the reservoir

Answer

A relief valve is a pressure-limiting safety device that opens when system pressure exceeds its set point, diverting excess flow back to the reservoir to prevent damage to pumps, cylinders, motors, and other system components.

Question 3

What happens if air enters a hydraulic system?

Accepted Answer

The system becomes spongy and erratic, with potential for cavitation and component damage

Answer

Air in hydraulic fluid is compressible, causing spongy and erratic actuator movement, reduced efficiency, increased noise, elevated temperatures, and potential cavitation damage to pump components.

Question 4

What is the purpose of a hydraulic accumulator?

Accepted Answer

To store pressurized fluid to supplement pump flow, absorb shocks, or maintain pressure

Answer

A hydraulic accumulator stores energy in the form of pressurized hydraulic fluid. It can supplement pump flow during peak demands, absorb pressure spikes and shocks, and maintain system pressure when the pump is off.

Question 5

What does the ISO cleanliness code measure in hydraulic fluid?

Accepted Answer

The number and size distribution of solid contaminant particles per milliliter of fluid

Answer

The ISO cleanliness code (ISO 4406) quantifies fluid contamination by reporting the number of particles per milliliter at three size thresholds: 4 microns, 6 microns, and 14 microns, expressed as range codes (e.g., 18/16/13).

Red Seal Millwright 433A Practice Test

Red Seal Millwright 433A Practice Test

433A Hydraulic Systems