flammability limit
explosive limit

The upper and lower flammability limits of methane in air are located on this line, as shown.

Temperature, pressure, and the concentration of the oxidizer also influences flammability limits.

The problem of defining flammability limits is very complicated, especially for solids and liquids.

The flammability limits of gases are expressed in proportions to the other gases present.

The terms "flammability limits" and "explosive limits" are used interchangeably.

The flammability range is delineated by the upper and lower flammability limits.

Hydrogen has very large flammability limits.

Although it has an upper flammability limit in air of 81%, acetylene's explosive decomposition behaviour makes this irrelevant.

When the concentration of gas reaches a critical value (the lower flammability limit), the gas suddenly catches fire in the presence of a flame.

If these products are sufficiently concentrated, within the flammability limits, and at a temperature above the ignition temperature, then combustion proceeds.

They are often associated with a gaseous mixture of fuel and oxidant of a composition, somewhat below conventional flammability limits.

Flammability limits refer to the fact that mixtures of gaseous fuels and air will only burn if the fuel concentration lies within well defined limits.

This causes the ullage fuel air ratio to increase rapidly and the ullage fuel air ratio to exceed the lower flammability limit.

HCCI engines have a small power range, constrained at low loads by lean flammability limits and high loads by in-cylinder pressure restrictions.

Flammability limits of mixtures of several combustible gases can be calculated using Le Chatelier's mixing rule for combustible volume fractions x:

Replies: My resource CRC Handbook of Chemistry and Physics gives the flammability limits of acetylene in air as: 2.5 to 80 % on a volume/volume basis.

Non hazardous areas on chemical and other plant are present where the hazardous gas is diluted to a concentration below 25% of its lower flammability limit (or lower explosive limit (LEL)).

In confinement, the range of composition of mixes of fuel and oxidant and self-decomposing substances with inerts are slightly below the flammability limits and for spherically expanding fronts well below them.

In most cases intact fuel tanks are very safe, as the tank is full of fuel vapour/air mixture that is well above the flammability limits, and thus cannot burn even if an ignition source were present (which is rare).

Lower flammability limit (LFL), usually expressed in volume per cent, is the lower end of the concentration range over which a flammable mixture of gas or vapour in air can ignite at a given temperature and pressure.

Though electrical components (such as a fuel pump) can spark and ignite fuel vapors, liquid fuel will not explode (see flammability limit) and therefore submerging the pump in the tank is one of the safest places to put it.

In other designs, stronger cases allow the fuel to be contained long enough for the fuel to heat to well above its auto-ignition temperature, so that, even its cooling during expansion from the container, results in rapid ignition once the mixture is within conventional flammability limits.

Presence of such smoke, soot, and/or brown oily deposits during a fire indicates a possible hazardous situation, as the atmosphere may be saturated with combustible pyrolysis products with concentration above the upper flammability limit, and sudden inrush of air can cause flashover or backdraft.

In 1965 he published data for flammability limits, autoignition, and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions.