🔍 Key Concepts

• 46 CFR requirements for automatic auxiliary boiler programming controls • Purpose of a prepurge in boiler operations (removing unburned fuel vapors with air before ignition) • What must happen automatically after a safety trip (flame failure or unsafe condition) in a properly designed boiler control sequence

💭 Think About

• Which of these options clearly matches a safety‑driven, regulatory requirement that must be built into an automatic control sequence, not just a design preference? • For each option, ask: does 46 CFR mandate this exact timing/behavior, or is the wording too specific or even unsafe? • Think about what the Coast Guard is MOST concerned with in boiler control sequences: preventing furnace explosions and ensuring adequate combustion air before and after fuel admission.

✅ Before You Answer

• Compare each choice against what you know about safe boiler start‑up/shutdown sequences (prepurge → light‑off → postpurge). • Ask whether a fixed "4‑second" ignition delay is actually a standard regulatory value in 46 CFR, or if timing is usually more flexible and system‑dependent. • Consider whether, after a safety trip, regulations would allow the control to simply avoid increasing air flow, or if the system must safely shut down and purge instead.