TB GAS Flashcards
What are the PROPERTIES OF NATURAL GAS?
2.0 GS
Natural gas is comprised mainly of methane but also contains ethane, propane and nitrogen.
Colorless
Odorless
o Mercaptan is added to natural gas giving it a distinctive rotten egg odor
Lighter Than Air
Explosive Range 5% - 15%
Ignition Temperature - 1163 Degrees Fahrenheit
Non-Toxic
Asphyxiant
NoN- Non Toxic C- Colorless O- Orderless A- Asphyxiant L- Lighter Than Air
What is The priority order of valve shutdown is?
pages 4,5,6,7,8 GS
1) Appliance Valve
2) Meter
A. Meter Valve
B. Master Meter
If possible, notify the utility company of your intention prior to shutting a master meter and inquire as to possible alternatives.
3) Head of Service Valve (Building Service Valve)
4. Exterior Gas Riser Valve
5) Curb Valve
If 1⁄4 turn does not shut the gas off, continue to turn the valve until resistance is met. This may occur at between 71⁄2 to 15 full turns. Do not turn the valve more than 15 times.
6) Street Valve (a.k.a. Line, Main or Isolation valves)
CAUTION: Do not operate street valves except under extreme circumstances and only upon direction of the Fire Department Incident Commander after consultation with the utility representative supervisor.
All MOMS have extra cooking skills A-Appliance Valve M- Meter H-Head of Service Valve E- Exterior Gas Riser Valve C-Curb Valve S-Street Valve
Flammable Natural Gas True/false?
o Explosive when confined: (4 walls, ceiling and floor)
If natural gas in the explosive range ignites in a CONFINED LOCATION, it will explode with destructive force.
o Flammable when UNCONFINED (outdoors): natural gas will ignite, NOT EXPLODE.
True 8.0 GS
Which of the following are correct? more then one..
A-Plastic pipe is not allowed to be used as gas pipe inside of a structure.But copper is.
B- Although easily folded, firefighters should not approach or attempt to fold leaking plastic gas pipe.
C-Always test for the presence of natural gas with a combustible gas indicator.
D- Do not touch or come near a leaking plastic gas pipe. The resulting spark can ignite the escaping gas.
E- All correct
Correct B, C D GS page 9 and 10
A -copper and plastic gas pipe not allowed inside a structure
Which of the following are correct? more then one..
A- notify the gas utility of water main breaks.
B-If you smell gas or suspect its involvement in a manhole fire, request the response
of the gas utility in addition to the electric utility.
C-If you can’t find the source of an indoor leak, take readings at traffic control boxes and manholes.
D-Before removing power from a building, ascertain if emergency power or a generator exists.
10.0 GS
A, B D are correct
C incorrect.
should read take readings at sewers and manholes
All of the following are correct except for one?
MINOR INDOOR GAS LEAK:
A- If the leaking gas is burning, allow it to burn until the gas supply is shut off. Combustible material near the burning gas should be wet down while waiting for the gas supply to be shut off. Shutting the gas supply is the safe way to extinguish a gas fire.
B- If gas is leaking indoors and not burning, the gas supply should be shut off and the area ventilated. A fog nozzle may be used for venting if necessary.
C- A leak or break in all low pressure gas piping may be stopped or greatly diminished by taping, stuffing rags, paper, etc., into break. This tactic will not work on high pressure piping.
D -If the Incident Commander deems it necessary, have Haz-Mat Company 1 respond.
E- At fires, the presence of window or wall mounted gas heating units must be communicated to the Incident Commander and their gas supply shut down.
page 11,12 GS
C incorrect
Not all low pressure pipes.
(Remember, do not touch or approach leaking plastic gas pipe.)
All of the following are correct except for one?
MAJOR INDOOR GAS LEAK:
A- Take gas readings with all available gas meters (Altair, Digital and Tiff). Special call a unit with an Altair digital gas meter if none is available at the scene. All special units including SOC support ladder companies carry sophisticated digital combustible gas indicators. If the Incident Commander deems necessary they should be special called.
B-Must ventilate if major indoor gas leak. Start venting at the upper levels of the building when possible and work your way down to the first floor and then out of the building.
C-Check at least three exposures on both sides of the occupancies with positive gas readings for the presence of a gas odor or leak including above and below the suspected leak. Evacuate and ventilate as necessary.
D- Do not pull the electric meter or open a circuit breaker. If power must be cut to the building, have it cut by the utility company at the pole or manhole.
page 13 GS
B incorrect
-Ventilate if it is safe to do so. If gas levels are above the flammable limits, they will drop into the flammable range as you ventilate. Start venting at the upper levels of the building when possible and work your way down to the first floor and then out of the building.
All of the following are correct except for one?
OUTDOOR GAS LEAK:
A- Dirt and debris may be seen blowing into the air from an excavation. This would indicate a high pressure leak. A loud roaring sound also indicates a high pressure leak.
B -Engine companies should be positioned at a safe hydrant and precautionary lines should be stretched to a safe location, out of the gas cloud, to protect exposures. Do not park over manholes or sewer gratings as gas may be venting from these locations.
C- If gas readings are obtained in ELECTRIC, SEWER or any other utility MANHOLE(S), the surrounding ELECTRIC, SEWER or any other utility MANHOLE(S) must be checked.
D- When arriving on the scene of a serious gas incident prior to the arrival of gas utility personnel and finding gas readings in an ELECTRIC MANHOLE, the following information shall be requested from the utility company via the FDNY dispatcher: The identity of the buildings(s) being supplied electricity by the involved
manhole(s).
E-If you detect gas readings inside buildings where the electricity enters the building (Electric Point of Entry or POE) request the location of the manhole that supplies electricity to the building and any other building(s) it supplies. Utilize this information to prioritize the checking of buildings for the presence of gas.
page 14 GS
C incorrect
If gas readings are obtained in ELECTRIC, SEWER or any other utility MANHOLE(S), the surrounding structures must be checked.
T/F?
SEWER MANHOLE COVERS
o Removal of SEWER MANHOLE covers can be performed by FDNY personnel
with the approval of an IC?
page 15
False on-sence chief officer
SEWER MANHOLE COVERS
o Removal of SEWER MANHOLE covers can be performed by FDNY personnel
with the approval of an on-scene Chief Officer.
T/F?
Removal of ELECTRIC MANHOLE covers by FDNY personnel may be performed only when requested by a utility company gas representative on the
scene and approved by an on-scene Chief Officer. Prior to requesting FDNY personnel to remove a manhole cover, the utility company gas representative must test the cover for stray voltage.
True page 15 GS
T/F?
DO NOT pull rectangular or square electric manhole covers. Any time the decision is made to remove a round manhole cover(s) the Chief Officer ordering such removal shall ensure the area around the manhole(s) is properly cordoned off to identify the hazard.
True page 15 GS
DO NOT pull any electric manhole covers if there is a manhole fire in the area or
if a smoking or arcing is observed in an electric manhole or transformer vault.
True page 15 GS
NOTES: Page 16
-Do not pull the electric meter or open a circuit breaker if gas is found in a building. Natural gas can infiltrate the meter and pulling it can generate a spark capable of igniting the leaking gas. If power to the building must be cut, have it cut by the utility company at the pole or manhole.
If gas is burning, do not attempt to extinguish it. Protect exposures with fog streams and wait for the utility company to stop the gas flow.
If the escaping gas is not burning, fog streams can be used to dissipate the escaping gas or to direct it away from threatened exposures.-
If the leaking pipe is in an excavation, avoid filling the excavation with water. Doing so will only hamper the repair process.
Notify your Officer whenever you shut a gas valve.
Notify the Incident Commander whenever a gas valve is shut.
Notify the gas utility company whenever a gas valve is shut by FDNY.
T/F?
Combustible Gas Indicator (CGI)- Tiff Meter
- If a flammable gas is present, it will click fasterand indicate hazardous in the atmosphere
13.0 GS
False. It does not indicate how hazardous the atmosphere is.
Combustible Gas Indicator (CGI)- Tiff Meter
Combustible gas indicators (CGI) are carried by all Battalions and Ladder companies. It is usually the first meter available on the scene. It is able to pinpoint leaks even in small amounts. It should be used in conjunction with a digital gas meter. When turned on in fresh air, it should be set to click slowly. If a flammable gas is present, it will click faster. It does not indicate how hazardous the atmosphere is. If the meter is clicking quickly, call for a unit with a digital combustible gas indicator.
T/F
-Units operating at premises with a gas leak that occurs before the main gas meter shall evacuate the building occupants where necessary and withdraw members to a safe location, preferably shielded by an object, in anticipation of a second explosion.
page 23 safety message
True
