CPT Fluid Systems & Hydraulics Flashcards
6 cards from real CPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CPT Fluid Systems & Hydraulics flashcards as text
Which type of pipe fitting creates a permanent, leak-free connection most suitable for high-pressure hydraulic lines?
Answer: Flared (JIC) fitting
JIC (Joint Industry Council) 37-degree flare fittings create metal-to-metal seals capable of withstanding high hydraulic pressures reliably.
What is the function of a flow control valve in a hydraulic actuator circuit?
Answer: Regulate the speed of the actuator by controlling fluid flow rate
A flow control valve restricts fluid flow to control actuator speed; less flow means slower movement, more flow means faster movement.
When troubleshooting a hydraulic system with slow actuator speed, which component should be checked first?
Answer: Pump output flow and relief valve setting
Slow actuation most commonly results from insufficient pump flow (worn pump) or the relief valve cracking open too early, both of which should be diagnosed before checking downstream components.
A hydraulic system loses pressure overnight with no visible external leaks. What is the most likely cause?
Answer: Internal leakage past a cylinder piston seal or directional valve spool
Internal leakage across worn cylinder piston seals or valve spools allows pressurized fluid to bypass, causing pressure to bleed down without external evidence.
What safety step must be performed before disconnecting a hydraulic line on a pressurized system?
Answer: Depressurize and de-energize the circuit, then verify zero pressure with a gauge
Residual hydraulic pressure can cause lines to whip violently or inject fluid into skin (injection injury), so circuits must be fully depressurized and verified at zero before disconnection.
Which condition causes hydraulic oil to turn dark brown or black over time?
Answer: Thermal degradation and oxidation from excessive operating temperatures
Sustained high temperatures cause hydraulic oil to oxidize, breaking down additives and base oil molecules, resulting in dark discoloration and acidic byproducts that damage components.