🔍 Key Concepts

• Look closely at how a cartridge-operated dry chemical extinguisher works – one action charges the cylinder with gas, and a different action releases the powder through the hose and nozzle. • Notice the parts labeled Gas Pressure Cartridge, Puncture Lever, and Squeeze Grip Valve and think about their separate functions. • Consider what the Cartridge Guard is protecting and whether it would normally be removed during use or left in place.

💭 Think About

• Which control must be used first to release gas from the small cartridge into the main extinguisher body, so that pressure can build up inside? • Once the extinguisher is pressurized, which control then allows you to start and stop the actual discharge of dry chemical from the hose and nozzle? • Is inverting this particular extinguisher necessary for it to work, or is that a feature of some older types not shown here?

✅ Before You Answer

• Verify which part is directly connected to the Gas Pressure Cartridge and would puncture or open it. • Confirm which handle or valve at the nozzle is used only to start/stop the flow after pressure is already available. • Make sure you understand that the Cartridge Guard is a fixed protective cover, not a normal step in the operation sequence.