When using a flammable refrigerant as a trace gas for leak detection, the amount must not exceed which of the following?

When using a flammable refrigerant as a trace gas for leak detection, the amount must not exceed which of the following?

• A. 25% of LFL
• B. 50% of LFL
• C. 10% of LFL
• D. 100% of LFL

Answer: (A)

When a flammable refrigerant is used as a tracer gas, safety requires keeping its concentration in air well below the flammable range. The lower flammable limit (LFL) is the minimum vapor concentration that can sustain a flame if an ignition source is present. To balance safety with effective leak detection, the amount used is limited to a safe fraction of the LFL—typically a quarter of that limit. This keeps the mixture non-flammable while still being detectable by leak detectors. If you used a larger fraction, you’d get closer to the flammable range and risk ignition; using a much smaller fraction would be safer but might not be reliably detectable.

When a flammable refrigerant is used as a tracer gas, safety requires keeping its concentration in air well below the flammable range. The lower flammable limit (LFL) is the minimum vapor concentration that can sustain a flame if an ignition source is present. To balance safety with effective leak detection, the amount used is limited to a safe fraction of the LFL—typically a quarter of that limit. This keeps the mixture non-flammable while still being detectable by leak detectors. If you used a larger fraction, you’d get closer to the flammable range and risk ignition; using a much smaller fraction would be safer but might not be reliably detectable.