🔍 Key Concepts
• Portable fire extinguisher maintenance requirements in 46 CFR (look at inspection and servicing intervals)
• How you can tell if an extinguisher is still fully charged: pressure gauge, liquid level, or weight
• Properties of different extinguishing agents (foam, soda acid, dry chemical, carbon dioxide) and how they are stored
💭 Think About
• Ask yourself: which type of extinguisher does NOT usually have a pressure gauge or sight glass to show the charge, so the only reliable way to check its charge is by weighing it?
• Think about which extinguishing agent is stored as a liquefied gas under high pressure in a seamless steel cylinder, where a relatively small loss in contents shows up as a noticeable loss in weight.
• For each choice, imagine how the crew would practically test whether it is still serviceable on board: what simple check (weight, gauge, shake test, liquid level) would make sense for that medium?
✅ Before You Answer
• Verify in the regulations which extinguisher must be weighed at least annually as part of its required inspection.
• Check which extinguisher type is specified to be removed and recharged ashore if the loss in weight is more than 10% of the full-charge weight.
• Confirm for each option whether, in normal practice, its condition is checked primarily by pressure gauge / seal / nozzle condition or by scale weight comparison.