Flashcards in Hazmat 1 Alternate Fuels Deck (23)
Properties of LP gases
1.2.1 LP gases are non-toxic and non-poisonous. They are however slightly anesthetic. When inhaled over a long period of time, LP gas will cause headache or nausea. Asphyxiation can occur due to oxygen displacement.
1.2.2 LP gas is odorless, an odorizing agent is added only when it is processed for domestic consumption.
1.2.3 LP gas is flammable.
1.2.4 In the liquid state, LP gases present a hazard similar to a highly volatile flammable liquid but with more rapid vaporization.
1.2.5 LP gases are heavier then air (1.5 to 2 times heavier).
When a tanker is on fire containing LP gas how far should we keep everyone not engaged in operations from the front and rear of the tanker and the sides?
Keep everyone, not actually engaged in operations, at least 1000 feet from the front and rear of the tank and 500 feet from the sides.
Can we extinguish a gas leak prior to the leak being stopped?
Do not extinguish the fire until the leak has been stopped, except under extremely unusual conditions.
When escaping gas is on fire and the flow cannot be shut off on a tank what is the FDNY's SOP to control the situation?
Where escaping gas is on fire and the flow cannot be shut off, application of large quantities of water on the tank and piping will permit controlled burning, allowing the fire to consume the contents of the tank without the danger of tank or pipe failure. Make certain that fire is NOT extinguished.
Tank failure under fire conditions usually occurs in what area of the tank?
Tank failure under fire conditions usually occurs in the vapor area of the tank when sufficient water cannot be applied to prevent the metal from softening or weakening to a point where metal failure occurs.
What are some of the warning signs prior to tank failure occurring?
Before tank failure occurs, the rise in pressure within the tank will cause an increase in the volume of fire, or a rise in the noise level or both. This may or may not be accompanied by a bubble or blister forming on the tank shell. When
any of these symptoms are present, the operating forces should be withdrawn to a safe area.
What is a effective way to disperse LP gas vapor if the gas supply cannot be shut off?
1.5.2 Water spray is effective in dispersing LP gas vapor. It should be used as soon as possible, directing the spray stream across the normal vapor path and dispersing the vapor to a safe location. Members handling the hose should avoid entering the vapor cloud and should keep low behind the spray so that they will be somewhat protected from radiant heat if the vapor should be ignited unexpectedly.
1.5.3 If water spray is not effective in dispersing the LP gas vapor, then heavy streams of water should be used from a safe distance.
Heat applied to the cylinder of a propane fueled vehicle will cause excessive pressure to build up in the cylinder opening the relief valve. How many times will one cubic foot of liquid expand as a gas?
One cubic foot of liquid will expand 270 times as a gas.
What are 2 main causes of a BLEVE in a Propane cylinder?
2.4.3 There is a great possibility that a cylinder involved in a fire will "BLEVE" (Boiling Liquid Expanding Vapor Explosion). A BLEVE can occur in a matter of minutes. A satisfactory performance of a relief valve can not prevent a BLEVE.
2.4.4 An impact failure of a cylinder in a transportation accident can also cause a BLEVE.
2.4.5 When a BLEVE occurs in a propane cylinder it will usually result in an explosion and fire ball with the cylinder becoming a flying missile.
The three areas of exposure during a vehicle leak or fire in a propane (LP-Gas) system are?
1. The engine compartment.
2. The fuel line from the tank to the automatic shutoff valve.
3. The tank area.
In a dual-fueled vehicle with both the gasoline and propane involved what is the correct procedure for controlling this fire?
Many vehicles are dual-fueled and use both propane and gasoline alternatively. A fire can originate with a gasoline leak and may eventually
involve both fuels. A BASIC PRINCIPLE IS THAT A PROPANE FIRE SHOULD NOT BE EXTINGUISHED EXCEPT BY SHUTTING OFF THE FLOW OF ESCAPING PROPANE.
It is important that we extinguish the gasoline fire by using foam, dry chemical or water spray and at the same time cooling the propane cylinder with hose streams to prevent a BLEVE.
If the tank area is involved in a fire, immediately locate where the tank relief valve discharges and keep clear of this area. Should the relief valve
function and discharge gas, the resulting discharge and possible fire could harm personnel. Direct water fog on the tank's outer surface to keep it
cool from the heat or flame impingement. Where are the locations of these relief valves on a passenger car and also on a tuck, van or bus?
C. The discharge point of the relief valve on passenger cars are positioned within 45 degrees of vertical. This could be located on top of the trunk or in the rear quarter panel or possibly off the rear bumper
F. Vans, trucks and buses have containers located in the rear section of the vehicle or mounted under the skirt or frame. The relief valve discharge must be piped to a safe area.
G. Determine the discharge point of the relief valve and keep all personnel away from this discharge point
The Brooklyn Union Gas Company, in conjunction with the Command Bus Company of Brooklyn, has been running a pilot program using CNG fueled buses since 1987.How many cylinders does each bus carry and how much gas does each cylinder hold?
Each cylinder contains 1100 cubic feet of gas and each bus carries nine (9) aluminum cylinders.
How are vehicles powered by compressed natural gas identified? where is the placard locations?
All vehicles powered by Compressed Natural Gas (CNG), which require a Fire Department permit to operate using such fuel, are required to have a warning placard on their front and rear bumper. Identification number 1971 in the diamond indicates that compressed natural gas is being used for propulsion. All other CNG powered vehicles registered in the state of New York are likely to be placarded only on the rear bumper. Vehicles originating outside of New York State are likely to be placarded in accordance with their applicable state regulations.
Note: There may be some states that do not require CNG powered vehicles to have any warning placard.
What are the Properties of compressed natural gas?
3.3.1 Natural gas is flammable.
3.3.2 Natural gas is non-toxic. Asphyxiation can occur due to oxygen displacement in an enclosed area.
3.3.3 Natural gas is lighter than air.
3.3.4 Natural gas is composed of 95% Methane and 5% other gases. The two terms Natural Gas and Methane are used interchangeably.
Can a CNG cylinder BLEVE under fire conditions?
CNG cylinders are subject to failure, but not to BLEVE's (Boiling Liquid Expanding Vapor Explosion) because they do not contain liquid.
Natural gas is lighter than air (2/3 as heavy) it will dissipate quickly. What can be used to assist in directing the flow to protect exposures?
1. A fog line can be used to direct the flow and protect exposures.
How do we control and extinguish a fire involving CNG cylinder?
A. Extinguish a fire by stopping the flow of gas.
B. If the flow of Gas can not he stopped do not extinguish the fire - let it burn.
C. Use a hose stream to cool cylinders and protect exposures.
How long does it take a vehicle to refill at a CNG refueling station using the Fast Fill method?
A. Fast Fill - In the fast fill system natural gas is stored in storage tanks under high pressure (3600 PSI) by the use of a compressor. The vehicle is refueled directly from these storage tanks in approximately 2 to 5 minutes.
How long does it take a vehicle to refill at a CNG refueling station using the Time Fill Method?
B. Time Fill Method - Under this system a vehicle is refueled directly off a gas compressor which is hooked up to a gas main. This method takes several hours to refuel a vehicle.
Properties of Methanol:
4.2.1 Methanol is a highly volatile flammable liquid.
4.2.2 It has a flash point of 54 F.
4.2.3 It is soluble in water.
4.2.4 Methanol vapors are slightly heavier then air and will flow along the ground collecting in low areas.
4.2.5 Methanol burns cleanly (little smoke) and its pale blue flame may be difficult to see in bright sunlight.
What type of foam must be used at a methanol fire?
What type of dry chemical extinguisher is most effective on a Methanol fire?
A. Methanol is destructive to ordinary foam. Alcohol type foam must be used. For small fires Type B dry chemical extinguishers are adequate.
Purple K is the most effective of the dry chemical extinguishing agents.