Which statement best summarizes the lube oil flashpoint categories?

Which statement best summarizes the lube oil flashpoint categories?

• A. 450 deg F - SAT 400-450, Minor Deg. 370-400, Major Deg. <370
• B. 350 deg F - SAT 300-350, Minor Deg. 250-300, Major <250
• C. 500 deg F - SAT 450-500, Minor Deg. 420-450, Major <420
• D. 400 deg F - SAT 350-400, Minor Deg. 320-350, Major <320

Answer: (A)

Flashpoint reflects how much the oil has degraded: the more degraded the oil, the lower the temperature at which its vapors can ignite. So the category system should show a high flashpoint for fresh oil and progressively lower ranges as degradation increases. The statement that lists Satisfactory around 400–450 °F, Minor Degradation 370–400 °F, and Major Degradation below 370 °F fits that pattern and is the best summary of how lube oil flashpoints map to condition. It captures the downward trend in flashpoint as oil becomes more degraded, which is the key idea. The other options give ranges that don’t align with that same progression, or place the degradation thresholds in ways that don’t match how degradation lowers the flashpoint.

Flashpoint reflects how much the oil has degraded: the more degraded the oil, the lower the temperature at which its vapors can ignite. So the category system should show a high flashpoint for fresh oil and progressively lower ranges as degradation increases. The statement that lists Satisfactory around 400–450 °F, Minor Degradation 370–400 °F, and Major Degradation below 370 °F fits that pattern and is the best summary of how lube oil flashpoints map to condition. It captures the downward trend in flashpoint as oil becomes more degraded, which is the key idea.

The other options give ranges that don’t align with that same progression, or place the degradation thresholds in ways that don’t match how degradation lowers the flashpoint.