A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Valve
Mechanical means for stopping and starting flow in a conduit; many types used in firefighting, including gate, foot, clapper (backflow preventers), sprinkler-heads, etc.

Vapor suppression
Process of reducing the amount of flammable or other hazardous vapors, from a flammable liquid, mixing with air, typically by careful application of a foam blanket on top of a pool of material.

Vehicle fire
Type of fire involving motor vehicles themselves, their fuel or cargo; has peculiar issues of rescue, explosion sources, toxic smoke and runoff, and scene safety.

Ventilation
Important procedure in firefighting in which the hot smoke and gases are removed from inside a structure, either by natural convection or forced, and either through existing openings or new ones provided by firefighters at appropriate locations (e.g., on the roof). Proper ventilation can save lives and improper ventilation can cause backdraft or other hazards.

Ventilation saw
A high-powered saw with metal-cutting teeth or disc for quickly making large openings in roofing materials.

Venturi effect
Creating a partial vacuum using a constricted fluid flow, used in fire equipment for mixing chemicals into water streams, or for measuring flow velocity.

Vertical ventilation
Ventilation technique making use of the principle of convection in which heated gases naturally rise.

Voids (building)
Enclosed portions of a building where fire can spread undetected.

Vollie
A volunteer firefighter.

Volunteer fire department
A group of part-time firefighters who are not paid when on-call, during incidents, or drills. Often professionally trained and equipped with state-of-the-art equipment.