Steam driven pumps are considered, by regulations, sources of vapor ignition if the steam temperature is at least what temperature?

Correct Answer: Option D — 500°F

Under USCG tank vessel regulations (46 CFR 30.10-69a), steam-driven pumps are classified as sources of vapor ignition if the steam temperature is 500°F (260°C) or higher. This threshold prevents the auto-ignition of flammable hydrocarbon vapors in the pump room or cargo spaces.