A pump tank extinguisher rated as 4-A can be expected to extinguish how much more fire than one rated 2-A?

A fire extinguisher rated with a number followed by an "A" classification, such as 4-A or 2-A, indicates its effectiveness against ordinary combustibles like wood and paper. In this system, the number represents the relative amount of fire the extinguisher can extinguish based on specific testing criteria defined by the National Fire Protection Association (NFPA).

For example, a 2-A extinguisher can put out a fire equivalent to 2.5 gallons of water, while a 4-A extinguisher is expected to extinguish the equivalent of 4.0 gallons of water. Therefore, when comparing the ratings, it is evident that the 4-A extinguisher can handle higher fire loads and extinguish twice as much fire as a 2-A extinguisher.

Thus, the correct understanding of these ratings leads to the conclusion that a 4-A rated extinguisher can extinguish twice as much fire as a 2-A rated extinguisher. This is why the answer indicating that the 4-A extinguisher can extinguish twice as much fire is accurate and reflects the established standards within fire safety.