fire engineering

• what does passive fire protection involve?

  this helps prevent fire instead of putting it out
• what does active fire protection involve?

  something that requires some action in order to work efficiently, may be manually operated like a fire extinguisher
• class A fires- organic solids like paper

  class B fires- flammable liquids

  class C fires- flammable gasses like methane

  class D fires- combustible burning metals like sodium

  electrical fires- caused by electrical equipment

  class F fires- involving fats such as cooking oils used in deep fryers etc
• what do fire detection systems do?

  they are designed to detect changes in the atmosphere produced by changes resulting from a fire. they are intended to detect the prescence of flame, smoke, gas, heat in the atmosphere that might have a harmful effect
• where are flame detectors used?

  where open flaming fires may be expected, they are responsive to flames more than 25 metres away
• what is the radius of heat detectors?

  it varies but about 5.3 metres
• how far should a person travel for a manual call point?

  a person should not have to travel more than 45 metres along as escape route or 25 metres for a disabled person
• what is the maximum sound level for a sounder?

  120 dBA
• what should the cables be like for in a fire system?

  fire resistant cabling is now required within the whole fire alarm system including the mains supply cables. all cables should be mechanically protected from floor level to 2 metres
• unless a detection circuit exceeds 1 km in length it is unlikely to give rise to a concern about voltage drop
• what is the smoke damper system?

  these involve rooftop vents to allow smoke and heat to escape they improve visibility for firefighters. they minimise property damage and confine a fire to a smaller area
• how do fire dampers work?

  they are installed in an air distribution system and are designed to close automatically upon detection of heat