Bleve Flashcards
(16 cards)
What are some steps to reduce BLEVES at rail tank car changes?
Heat retardant wrap under shell of tank
Insulation under shell
Heat shields at the most common points of impact
Locking tank car couplers (eliminate punctures)
Flame retardant spray
4 steps to reduce the risks of BLEVEs at bulk stations
Emergency shut-off valves Excess flow and back flow valves Heat detectors that sound alarms Water deluge system Fixed water sprayers
How full are tanks filled?
85% to leave room for pressure expansion
Tank container sizes
10 000 gallon tanker trucks
30 000 gallon rail tankers
BLEVEs can explode and burn people how far away?
1000 feet
What does prv stand for?
Pressure release valve
Main points to consider when approaching a BLEVEs
Is there a leakage that may result in fire?
How long has the tank been inflamed?
How much water is available?
What threats to life and property ?
Propane is pressurized to store and transport as a liquid. At what rate is it pressurized?
270 times it’s volume
Plg- pressurized liquid gas
At what temperature can propane no longer be maintained as a liquid?
97 degrees Celsius
True or false,
Only flammable substances can BLEVE
False
The danger zone for projectiles
Over 1000 m
Tanks can BLEVE between 3-12 minutes depending on size. What are the times given for each size?
BBQ tanks 2-3 mins
400 L tanks 3-4 mins
4000 L tanks 5-7 mins
40 000 tanks 8-12 mins
Four main dangers with BLEVEs
Fire
Thermal radiation
Pressure from blast
Projectiles
Fire ball radius
400 l 18 metres
4000 l 38 metres
40000 81 metres
Thermal radiation rule of thumb (distance)
4 x the radius of the fireball to a minimum of 90 metres
400 l 90 metres
4000 150 metres
40000 320 metres
A 40 000 litre tank requires how much water to successfully cool the tank?
2000 litres a minute
