Hazmat Chap 1- Alternate Fuels Flashcards
LP…
liquefied petroleum gases -stored as liquid under pressure -vaporize as gas -referred to as "bottle gas" -odorless -flammable HEAVIER than air(1.5 - 2 times)
Basic precautions at LPG Gas Fires/Emergencies…
approach fire/leak from UPWIND
- keep nozzle low and aim upwards
- clear out persons in vapor cloud
- evacuate person in path of vapor cloud immediately
- shut off all sources of ignition at the SAME TIME
Everyone, NOT ACTUALLY ENGAGED in operations…
at least 1000 feet from the front and rear of the tank
and
500 feet from the sides
Do not extinguis the fire until the leak has been stopped…except…?
Under extremely unusual conditions
If only valve that can be used to stop flow of gas is involved in fire or exposed to heat or flame…consider?
using a HEAVY FOG STREAM to protect member while he shuts valve
- proceed SLOWLY to prevent flashback
- wear masks and protective fire clothing
Tanks surfaces exposed to heat, either from auto exposure or fire from another source…can be protected by…?
applying LARGE quantities of water on them
Where escaping gas is on fire and flow cannot be shut off, application of large quantities of water on the tank and piping will permit CONTROLLED BURNING..
allowing fire to consume the CONTENTS of the tank, without danger of tank or or pipe failure…make certain…fire is NOT EXTINGUISHED
What is effective on small LP gas fires?
PORTABLE DRY CHEM
applied at BASE of the fire
CARBON DIOXIDE EXTINGUISHERS CAN ALSO BE USED
-tank failure usually occurs in VAPOR area
Before tank failure occurs, rise in pressure will cause an …
INCREASE in the volume of fire or rise in NOISE LEVEL, or both…may or may not be accompanied by a bubble or blister forming on tank shell
ANY of these symptoms present, OPERATING forces should be withdrawn to safe area
Normally no attempt should be made to move a tank involved in fire….HOWEVER
It conditions develop that make it desirable to move tank, it should be moved in an UPRIGHT position
-NEVER drag it in a manner that might further damage valves or piping
-PORTABLE LP GAS CYLINders exposed to a serious fire should be removed to safe location
LP Gas LEAK WITHOUT FIRE…
- close ANY valve available to stop flow of gas
- small lines (copper tubing) can be flattened to stop flow
- vehicles involved- consult driver
- storage facilities- consult plant personnel
Is water spray effective in dispersing LP gas vapor?
YES…used as soon as possible..disperse vapor to safe location
- avoid entering vapor cloud
- keep low behind spray/protected from radiant heat
if water spray is not effective in dispersing LP gas vapor, then heavy streams of water from safe distance
Propane fueled vehicles
- mostly dual-fueled vehicles-GASOLINE AND PROPANE
- buses/vans/autos
- signs or placards to identify
- finding a PROPANE CYLINDER is a positive means of identification
- Propane is an LPG
Propane…
- liquified gas stored in cylinders at temp above its boiling point -remains under pressure as long as container remains closed
- heat applied in the cylinder will cause excessive pressure to build up in the cylinder opening the relief valve
- cylinder involved in fire can ‘BLEVE’
- 1 cubic ft of liquid will expand 270 times as a gas
impact failure of a cylinder in a transportation accident can also cause a BLEVE
BLEVE in propane will result in explosion/fireball with cylinder becoming missile
Leaks/Spills…
- eliminate sources of ignition
- evacuate immediate area:down wind/low areas (cellars), where life hazard greatest
- use fog streams
- control leak
- utilize combustible gas detector
Fires…
do not extinguish fire unless leak can be stopped…protect exposure with hose streams
-cylinders exposed to fire and heat should be cooled by hoselines so they don’t BLEVE
The 3 areas of exposure during a vehicle leak or fire in a propane (LP-Gas) system are ?
1-Engine compartment
2-fuel line from the tank to automatic shutoff valve
3-tank area
many vehicles are dual fueled
basic principle- PROPANE FIRE should not be extinguished except by shutting off flow of escaping propane
gasoline can be extinguished by foam, dry chemical or water spray and at same time cooling propane cylinder
All vehicles powered by CNG (compressed Natural Gas) which require an FD permit to operate using such fuel…are required to have…?
PLACARD on front and rear bumper
identification 1971 indicates CNG used
- all other CNG powered vehicles registered in NYS will likely be placarded in rear bumper only
- some state may not require placards
Natural Gas…
- flammable
- non toxic/asphyxiant
- LIGHTER THAN AIR
- natural gas and methane are interchangeable
CNG…
pressurized in cylinders up to a pressure 3,000PSI
CNG do NOT BLEVE..because they do not contain liquid
CNG Leaks….vehicles
- eliminate ignition sources
- evacuate
- natural gas LIGHTER than air–dissipate quickly
- fog line to direct flow and protect exposures
Control leak….
stop flow-each vehicle has emergency shut off
- sign “emergency shut off”
- common gas valve 1/4 turn (each CNG cylinder shut off individually, turn clockwise
- stretch line to protect occupants members
Fire CNG…
- extinguis fire by stopping flow of gas
- if the flow of gas can not be stopped- do not extinguish fire…let it burn
- use a hose stream to cool cylinders and protect exposures
CNG filling station can service?
1-28 vehicles at a time
fast fill–3600 psi/2-5 minutes..filled from storage tanks
Time fill-directly off gas compressor, which is hooked up to gas main(this will take several hours)
Fire protection at CNG filling station…
20 lb dry chem extinguisher
- heat/ultraviolet fire detectors
- automatic shut off gas supply
- manual shutoff for gas supply…1/4 turn and plainly marked
- fusible plug set for 212 degrees
- burst disk set for 4700 PSI
-some have Halon or deluge water extinguishing systems
Methanol fueled vehicles…
highly volatile flammable liquid
flash pt 54 degrees F
Heavier THAN AIR-will flow along ground
methanol burns cleanly-little smoke and pale blue flame
-eye and skin irritant
-inhalation can cause drowsiness, blurred vision, death
-effects may delay 24 hrs
eliminate ignition sources evacuate area use fog streams prevent liquid from entering manholes dike with sand /dirt
Methanol is destructive to ordinary foam..
ALCOHOL type foam MUST be used
-small fires type B- dry chem
Purple K is most effective
application of large amounts of water will dilute the methanol rendering it NON FLAMMABLE…concentration must be reduced below 20 percent to be effective
T or F ….METHANOL fires can be INVISIBLE during day light hours…
TRUE
