Fire Protection and Prevention Basics

A chemical reaction between a fuel and an oxidizing agent that produces energy, usually in the form of heat and light.

The amount of heat in calories released when 1 gram of a substance burns completely.

Any liquid with a flash point between 140°F and 200°F.

Any liquid with a flash point below 140°F and a vapor pressure not exceeding 40 psia at 100°F.

The lowest temperature at which a liquid produces enough flammable vapor to ignite in air.

The highest concentration of a flammable substance in air that will still burn; above this point, the mixture is too rich to burn.

The lowest concentration of a flammable substance in air that will still burn; below this point, the mixture is too lean to burn.

These types of fires involve energized electrical equipment like wiring, controls, motors, and appliances.

This class includes fires involving combustible metals such as magnesium and sodium.

These fires involve combustible cooking media such as oils and grease commonly found in commercial kitchens.

A system where water is present inside the piping distribution system at all times.

A system installed in areas prone to freezing temperatures, where water is not present until a fire occurs.

A fire extinguisher's hydrostatic test is an exception when the unit has been repaired with soldering, welding, brazing, or patching compounds.

A fire extinguisher's hydrostatic test is an exception when the cylinder or shell threads are damaged.

A fire extinguisher's hydrostatic test is an exception when corrosion exists, including pitting under removable name plate assemblies.

A fire extinguisher's hydrostatic test is an exception when the extinguisher has been exposed to fire or used with a calcium-chloride-based agent.

A sprinkler system where water is not present in the pipes until the system is triggered. The water is released into the piping distribution system when a fire is detected.

A sprinkler system designed for areas with special hazards where rapid fire spread is a concern. Heat sensors are removed from the sprinkler heads, and the system is activated by a fire alarm system.

A sprinkler system with no water stored in the pipes. Water is released by activating a deluge valve, which is triggered by a fire alarm system. The discharge nozzle spray patterns are designed to protect specific hazards, such as three-dimensional components or equipment.

A hybrid sprinkler system combining elements of wet, dry, and deluge systems. A water supply valve is added to a dry pipe system, and this valve is opened by a fire detection system.

This sprinkler system releases a mixture of water and low-expansion foam concentrate. It is used for areas with high-challenge fires, such as flammable liquids and airport hangars.

The lowest temperature at which a substance will ignite in the air without an external spark or flame. It's like the 'ignition point' for self-burning.

The density of a liquid compared to water. Liquids with specific gravity less than 1 are lighter than water, while those with 1 or more are heavier.

The density of a gas or vapor compared to air. Gases with vapor density greater than 1 are heavier than air, while those less than 1 are lighter.

The rate at which a liquid turns into gas under specific conditions. A value of 1 is the standard, so anything less than 1 evaporates faster.

The maximum amount of a substance that can dissolve in water at a specific temperature and pressure. This is often used in environmental studies.

The pressure exerted by the vapor phase above the liquid surface.Think of it as the 'push' from the escaping vapors.

The temperature at which a liquid will continuously burn after ignition. It`s the point where the liquid is hot enough to keep the fire going.

The range of concentrations between the lower and upper limits where a mixture of a substance with air is flammable or explosive.Think of it as the 'sweet spot' where the mixture is just right to burn.

Areas where the quantity and/or combustibility of contents is low and where fires with relatively low rates of heat release are expected. Think of a regular office with not a lot of flammable materials.

Areas where the quantity and/or combustibility of contents is medium and where fires with medium rates of heat release are expected. Think of a storage room with a moderate amount of flammable materials.

Areas where the quantity and/or combustibility of contents is high and where fires with high rates of heat release are expected. Think of a chemical plant with a high concentration of flammable materials.

The maximum allowed distance between sprinklers in an occupancy area. Think of it as the safe space between sprinkler heads.