Safety and Compliance Flashcards

A technician needs to pressurize a system to check for leaks. Which gas is the safest and most appropriate choice?

Answer: Dry nitrogen through a pressure regulator

Dry nitrogen is inert and moisture-free, and a regulator keeps it from over-pressurizing the system.

Why must oxygen never be used to pressurize a refrigeration system?

Answer: It can explode when it contacts compressor oil

Oxygen under pressure reacts violently with oil and can cause an explosion.

What is the maximum temperature a refrigerant cylinder should ever be exposed to?

Answer: 125°F

Above 125°F, the liquid inside can expand until the cylinder is hydrostatically full, and it may rupture.

A large refrigerant leak happens in a basement equipment room. What is the main immediate danger to people in the room?

Answer: Suffocation, because refrigerant vapor pushes out the oxygen

Refrigerant vapor is heavier than air, collects in low spaces, and pushes out the oxygen people need to breathe.

What toxic gas can form when refrigerant vapor touches an open flame or a very hot surface?

Answer: Phosgene

Heat breaks down CFC and HCFC refrigerants into phosgene and acids, which are highly toxic.

How full can a refrigerant recovery cylinder be filled with liquid?

Answer: 80% of its capacity

Filling to no more than 80% leaves room for the liquid to expand as it warms.

What colors identify an approved refrigerant recovery cylinder?

Answer: Gray body with a yellow top

Recovery cylinders have a gray body and a yellow shoulder or top.