Mechanical Systems & Equipment Maintenance Flashcards

A hydraulic system pressure gauge reads normal but the actuator moves slowly. The most likely cause is:

Answer: Internal leakage past a worn control valve spool

Internal valve spool leakage allows flow to bypass the actuator, reducing speed while maintaining gauge pressure.

When replacing a timing chain or belt, technicians must ensure the:

Answer: Timing marks on the crankshaft and camshaft are aligned

Proper alignment of timing marks ensures correct valve timing relative to piston position.

A shaft keyway coupling transmits torque primarily through:

Answer: A key seated in mating keyways on the shaft and hub

The key transfers torque by bearing against the sides of the keyways cut into both the shaft and the hub.

Which maintenance strategy uses real-time equipment condition data to schedule repairs only when needed?

Answer: Predictive maintenance

Predictive maintenance monitors equipment condition parameters to forecast failure and schedule intervention before breakdown.

When tightening a bolted flange joint in a pressurized piping system, the correct procedure is to:

Answer: Tighten all bolts to 25% torque in a star (cross) pattern, then increase in stages

A cross-pattern, multi-pass torquing procedure ensures even gasket compression and prevents leaks.

What type of coupling is used to connect two shafts when slight angular misalignment cannot be avoided?

Answer: Jaw (spider) flexible coupling

Jaw flexible couplings tolerate minor angular, parallel, and axial misalignment through the elastomeric spider insert.

The function of a pressure relief valve in a hydraulic circuit is to:

Answer: Limit maximum system pressure to prevent component damage

A pressure relief valve opens when system pressure exceeds its set point, diverting flow back to tank to protect components.