Terms B Flashcards
Backdraft
a deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion.
Backing
slow extension of a fire down-slope or into wind in the opposite direction of its main spread.
Bead
a rounded globule or re-solidified metal at the end of the remains of an electrical conductor that was caused by arcing and is characterized by a sharp line of demarcation between the melted and unmelted conductor surfaced.
Blast pressure front
the expanding leading edge of an explosion reaction that separated a major difference in pressure between normal ambient pressure ahead of the front and potentially damaging high pressure at and behind the front.
BLEVE
boiling liquid expanding vapor explosion.
Boiling point
the temperature at which the vapor pressure of a liquid equals the surrounding atmospheric pressure. For purposed of defining the boiling point, atmospheric pressure shall be considered to be 14.7 psia (760 mm Hg or 101.4 kPa). For mixtures that do not have a constant boiling point, the 20 percent evaporated point of a distillation performed in accordance with ASTM D86, Standard Test Method for Distillation of Petroleum Products at Atmospheric Pressure, shall be considered to be the boiling point.
Bonding
the permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed.
Brand circuit
the circuit conductors between the final overcurrent device protecting the circuit and the outlets(s).
Brisance
the shattering effect of power of an explosion or explosive.
British thermal unit (Btu)
the quantity of heat required to raise the temperature of one pound of water 1°F at the pressure of 1 atmosphere and temperature of 60°F; a British thermal unit is equal to 1055 joules, 1.055 kilojoules, and 252.15 calories.
