Industry Best Practices Flashcards

What is the maximum level you should fill a refillable recovery cylinder?

Answer: 80% of capacity

Filling past 80% leaves too little vapor space for liquid expansion, which can rupture the cylinder.

What color scheme identifies a recovery cylinder?

Answer: Gray body with a yellow top

Recovery cylinders are gray with yellow tops (shoulders) to tell them apart from new refrigerant containers.

How often must a refillable DOT recovery cylinder be hydrostatically retested?

Answer: Every 5 years

DOT requires recovery cylinders to be hydrostatically retested every 5 years, and the test date is stamped on the cylinder.

Which practice speeds up refrigerant recovery the most?

Answer: Removing Schrader valve cores with a core-removal tool

Schrader cores restrict flow, so removing them and using short, large-diameter hoses greatly speeds recovery.

When using dry nitrogen to pressurize a system for leak testing, what equipment is required?

Answer: A pressure regulator and a relief valve

A nitrogen cylinder holds over 2,000 psi, so a regulator and relief valve keep the system from being overpressurized.

Why should oxygen or compressed air never be used to pressurize a refrigeration system?

Answer: They can cause an explosion when mixed with compressor oil under pressure

Oxygen or air mixed with oil under pressure can ignite or explode.

What is the best practice for recovering different refrigerants on the same job?

Answer: Use a separate dedicated cylinder for each refrigerant

Mixed refrigerants often can't be reclaimed and may need costly destruction, so each refrigerant gets its own cylinder.