Basic Operations Firefighter Certification Practice Exam

What are the two basic designs for handheld dry chemical extinguishers?

1. Portable and fixed

2. Coiled and manual

3. Cartridge and stored pressure

4. Single-use and refillable

The correct answer is: Cartridge and stored pressure

The two basic designs for handheld dry chemical extinguishers are cartridge and stored pressure. In the cartridge design, the expellant gas (often nitrogen) is stored in a separate cartridge, which is only activated when the extinguisher is used. This design allows for a higher pressure and is generally easier to refill since the cartridge can be replaced. It's typically found in extinguishers that are intended for industrial or specialized use. On the other hand, stored pressure extinguishers have the expellant gas stored in the same cylinder as the extinguishing agent. This design maintains a constant pressure on the extinguishing agent, allowing for immediate operation. Stored pressure extinguishers are commonly used in residential and commercial applications due to their simplicity and reliability. Understanding these designs is crucial for firefighters as it impacts both operational procedures and maintenance practices.