The Fire Triangle & The Dust Explosion Pentagon , The Fire Diamond

The “Fire Triangle” is a graphic representation of a concept, used to list the following prerequisites of an explosion:-

FUEL  (Flammable Material in form of GAS or Vapors )

Oxygen from the air

IGNITION or Spark

The FIRE TRIANGLE refers to the elements required for an explosion without any details of the other important parameters . For example :The ignition energy , the composition of the oxygen-vapor mixture by volume with reference to the :

UPPER EXPLOSIVE LIMIT

LOWER EXPLOSIVE LIMIT

Slide show : Working of a Fire Triangle

The presence of  TWO additional elements make conditions favorable for a COMBUSTIBLE DUST EXPLOSION

The combination of these five elements generate a Dust Explosive Pentagon. Dust Explosion Pentagon is another concept . -Fuel , which in this case is combustable dust -Dust to be in form of a cloud (Dispersed particles suspended in air)   -and Confined in a space -Oxygen -Ignition Source (Fire-starter)

The Fire Diamond

Fire Diamonds (National Fire Protection Assiciation -704) belong to a family of pictogram related to the Ex industry. This one is usually pasted or printed on containers of dangerous chemicals.Similar pictogram are painted on carriers (Trucks , tankers or lorries ) of the dangerous chemicals. This pictogram, known commonly as Fire Diamond, is mainly used in the USA.

Symbolism

The four divisions are typically color-coded, with – blue indicating level of health hazard, – red indicating flammability, – yellow (chemical) reactivity,    and white containing special codes for unique hazards. Each of health, flammability and reactivity is rated on a scale from 0 (no hazard; normal substance) to 4 (severe risk). (Ref: Wikipedia)