ASF Tools and Equipment Usage Flashcards

Which type of wrench is preferred when tightening refrigerant line flare fittings to avoid over-tightening?

Answer: Torque wrench

A torque wrench allows the technician to apply the manufacturer-specified torque to flare fittings, preventing leaks from under-tightening or cracked fittings from over-tightening.

What does an electronic leak detector primarily sense when checking a refrigeration system?

Answer: Trace amounts of refrigerant gas in the air

An electronic leak detector uses a heated diode or infrared sensor to detect trace concentrations of refrigerant vapor escaping from fittings, joints, or coils.

Which tool would a technician use to cut copper refrigerant tubing cleanly without creating metal shavings inside the line?

Answer: Pipe cutter (tubing cutter)

A tubing cutter uses a hardened wheel to score and shear copper tubing cleanly, minimizing burrs and keeping metal debris out of the refrigerant circuit.

What is the purpose of a nitrogen purge when brazing refrigerant lines?

Answer: To prevent internal oxidation and scale formation inside the tubing

Flowing dry nitrogen through the tubing during brazing displaces oxygen, preventing copper oxide scale that could later contaminate compressor valves and metering devices.

A micron gauge is used during refrigeration system service to verify what?

Answer: Depth of vacuum achieved

A micron gauge measures vacuum depth in microns of mercury, confirming the system has been evacuated deep enough (typically below 500 microns) to remove moisture and non-condensables.

When should a technician replace the oil in a vacuum pump?

Answer: After each use or when the oil appears cloudy/dark

Vacuum pump oil absorbs moisture and contaminants during evacuation; cloudy or discolored oil loses its ability to achieve deep vacuums and should be replaced regularly.