🔍 Key Concepts

• Cartridge-operated fire extinguishers and how they differ from stored-pressure types • Function of the gas pressure cartridge shown inside the extinguisher body • What happens inside the extinguisher when the puncture lever is operated

💭 Think About

• Look at the internal cutaway: when you move the puncture lever, what component does it act on, and what change does that cause inside the cylinder? • Which part of the extinguisher actually provides the driving pressure to expel the agent, and how is that pressure released? • Compare the puncture lever with the carrying handle and hose: which parts are clearly for handling, and which control the internal gas flow?

✅ Before You Answer

• Trace the path from the puncture lever to the gas pressure cartridge in the illustration and note their mechanical connection • Decide which single action must occur first before the extinguishing agent can leave the nozzle: that is the role of the lever • Confirm that the lever’s function is different from simply carrying or mounting the extinguisher and is not used to measure charge like a pressure gauge would