Core Concepts and Principles Flashcards

What is the maximum amount a refillable refrigerant cylinder should be filled?

Answer: 80% of its liquid capacity

Leaving 20% vapor space allows for liquid expansion as temperature rises.

What colors identify a DOT-approved refrigerant recovery cylinder?

Answer: Gray body with yellow top

Recovery cylinders are gray with yellow shoulders or tops.

How often must refillable refrigerant recovery cylinders be hydrostatically tested?

Answer: Every 5 years

DOT requires refillable cylinders to be hydrostatically retested every five years, with the date stamped on the cylinder.

Before disposing of a disposable (non-refillable) refrigerant cylinder, the technician should:

Answer: Recover remaining refrigerant to 0 psig and render the cylinder useless

Empty disposable cylinders are recovered to 0 psig, then punctured or marked empty before recycling as scrap metal.

What information must accompany a cylinder of used refrigerant being shipped to a reclaimer?

Answer: DOT classification tag and label showing refrigerant type and quantity

Shipped cylinders need DOT labeling and a tag identifying the refrigerant type and amount.

Why should refrigerant cylinders never be heated with an open flame or stored above 125°F?

Answer: Pressure can rise enough to rupture the cylinder

Heat raises cylinder pressure rapidly and can cause a rupture or explosion.

What gas should be used with a pressure regulator to pressurize a system for leak testing?

Answer: Dry nitrogen

Dry nitrogen is inert and safe, while oxygen or air can explode when mixed with compressor oil under pressure.