Hydraulic Systems and Schematics Flashcards
6 cards from real Millwright Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Hydraulic Systems and Schematics flashcards as text
What is the primary function of an accumulator in a hydraulic system?
Answer: To store pressurized fluid for peak demand and absorb pressure spikes
Hydraulic accumulators store energy in the form of pressurized fluid to supplement pump flow during peak demand, absorb shock from pressure spikes, and maintain pressure during brief pump outages.
A hydraulic cylinder extends slowly but retracts at normal speed. What is the most likely cause?
Answer: The piston seal is leaking, allowing fluid to bypass
A leaking piston seal allows fluid to bypass from the pressure side to the return side internally. The extend stroke is slower because the full bore area requires more flow, amplifying the effect of internal leakage.
What does a diamond shape with a diagonal line through it represent on a hydraulic schematic?
Answer: A heat exchanger
On hydraulic schematics, a diamond shape with a diagonal line represents a heat exchanger (cooler), used to remove excess heat from the hydraulic fluid.
Why is it important to check for air in a hydraulic system after maintenance?
Answer: Air is compressible and causes spongy operation, heat, and accelerated fluid degradation
Air trapped in hydraulic fluid is compressible, causing erratic actuator movement, spongy controls, excessive heat from compression, and fluid oxidation that degrades seals and components.
What is the purpose of a counterbalance valve in a hydraulic circuit?
Answer: To prevent uncontrolled movement of a load that could overrun the pump flow
A counterbalance valve prevents a suspended or gravity-loaded actuator from dropping uncontrollably by requiring pilot pressure to open, ensuring the load moves only as fast as the pump delivers fluid.
What does a hydraulic system pressure gauge reading that fluctuates rapidly indicate?
Answer: Air in the system or a failing pump
Rapid pressure fluctuations typically indicate air entrainment in the fluid (causing compressibility effects) or a pump with worn or damaged internal components producing inconsistent output.