Book 29 Flashcards
common source of heat in buildings due to its convenience, abundance, and relatively low cost
Natural gas
natural gas delivered to the property, via
underground service pipes
Pure natural gas is completely
odorless
For the purpose of leak detection, what is added so that as little as 1% of natural gas in the air can be detected?
Odorant
What is the common odorant , which is used in solution of 1 pint per million cubic feet of gas?
Mercapitan/Thiophane Mix
Natural gas, when inhaled in limited concentrations is considered what?
Non-toxic and not hazardous
Is natural gas lighter or heavier than air?
Lighter
Natural gas has a ignition temp of what?
1100 degrees
Natural gas has a flammable range between?
4 and 14 percent
What do transmission lines of natural gas maintain pressure up too?
1000 psi
What are used to maintain appropriate flow and pressures for natural gas?
Booster compressor stations at specific intervals
To compensate for fluctuating, what do gas companies maintain?
Underground or above ground storage facilties
How is natural gas generally distrusted by?
Combination oof transmission lines and distribution lines
Transmission lines bring natural gas into the Southern Cali area and vary in diameter from
12 to 36 inches
How is natural gas distributed to Gas Company Customers?
By distribution mains
Gas is carried by service lines, as medium pressure, which normally does not exceed what psi?
60 psi
At the service meter (Meter Set Assembly) the pressure is reduced to a low pressure (approximately what psi?
1/3 psi
What are distribution lines generally made of ?
Polyethylene
What are older existing gas distribution mains made of?
Steel or cooper, rare to find
What color are the polyethylene gas mains?
Yellow, national color code for newer installations
What color are older gas mains?
Plastic pipe can be pink (salmon beige) or orange in color
What will be running the length of the pipe for location plastic gas lines below ground?
Wire
What type of material will be gas pipes above ground?
Steel
Where are gas distribution mains normally located?
Underneath city streets Parallel to curbs Under grassy parkways Between the curb and sidewalk Occasionally in alleys
How is natural gas distributed from a distribution main to the customer?
By a service line
How is the pressure for a customer line regulated and measured?
By a regulator and gas meter
Gas companies refer to gas meters as what?
MSA= meter set assemblies
Where can meter set assemblies be located at?
- Outside sets: outside the structure
- Underneath sets: underneath structures, stairs, etc.
- curb meter box: vault underneath a sidewalk
- cabinet set: enclosure on the exterior of the structure
What are MSA categorized as?
Residential
Industrial
Multiple Gas Meter
The basic MSA consists of what?
Piping
Shut-off valve
Regulator
Gas Meter
The pipe rising vertically from the ground close to the exterior wall of structure is called a what?
Riser
Tracing the riser up from the ground the first fitting is the shut -off valve called the what?
Stopcock or service cock
-primary concern for shutting off the gas to a structure
A ring on the stopcock valve indicates what?
Branch service
A flat washer on the stopcock valve indicates that the service line is a what?
Plastic pipe inserted inside a older metal pipe
A band on the stopcock valve indicated the service line is what?
Plastic
Up the riser, past the stopcock, is a flat circular device called a what?
It reduces medium gas pressure up to what psi to a relatively low level of approximately what?
Regulator
60 psi to 1/3 psi
The gas meter measures what?
The amount of gas that is used
When locating a MSA what do you initially look for?
A “G” - either chiseled or painted on the curb
Required by Cal-OSHA, marks the location where the service love passes beneath the curb and indicated which side of the building the MSA is located
Where are MSAs and shut-off valves normally located at?
Outside wall of a structure. Location is easily accessible to gas company personnel who read the meters for billing purposes
If an MSA is not visible along an outside wall, it us usually found in what following locations?
- Crawl space, under building
- beneath outside staircase
- outdoor cabinet, new condos
- underground garage
- sidewalk or parkway vault, side of building
- basement, shut-off usually accessible from outside building
- subsurface, parkway or sidewalk
Some MSA’s may be equipped with an emergency vibration-sensitive shut-off device known as what?
Earthquake valve
Marketed by private industry and are normally mounted on the discharged side, right side as you face the meter, of the MSA
What may possibly shut off the flow of gas?
Swift-kick
How do you reset the Earthquake valve?
Turning a reset button, one-quarter turn, completes reset of this device
In Industrial MSA’s, what can be used to utilized to control the flow of gas in the service main
-curb valve & curb valve extension handle
Industrial shut- off valves that are used for high pressure applications are known as what?
Nordstrom Valves
Nordstrom valves are larger than standard shut-off valves and may require more effect and larger tools to shut off the flow of gas. Some have gate valves with wheel handles, which direction do you turn it to close?
Clockwise
Industrial applications that are high pressure can use how many regulators in series to regulate the gas pressure?
Two regulators
What type of meter is used to regulate the high pressure and handle quick surges?
Rotary meter
Meters under the sidewalk are called what and common in what area?
Curb meters, commercial areas
The lid over the curb meter is made of what?
Lightweight concrete or fiberglass set in a metal frame
How can a curb meter be easily identified?
Gas company markings
Industrial MSA’s are physical what than MSAs used for residential applications?
Physically Larger
Multiple habitational or commercial occupancies are often equipped with multiple what?
MSA’s:
Provide a master stopcock and a separate meter and stopcock for each unit
Who is required to identify the individual MSA’s, as to which unit or building they serve?
GAs Co.
Who do you notify if the identification of has worn away and can have the meters properly marked?
Gas Co.
In some commercial areas, multiple structures may be commonly serviced by a single service pipe called what?
Standard service main
What identifies a standard service man that multiple structures may be commonly serviced by a single service pipe?
A metal ring
In a branch service, the occupancy that s further from the supply main is a what?
The occupancies are what?
Standard Service/Branch service
All MSA’s that are served from the branch main will be identified by what?
A ring at the stopcock
To turn off the flow of gas, turn the ____, _________, to the flow of gas; crosswise to the pipe
Tang; crosswise
What shape can the tang on some stopcock be?
Square
Tangs can be easily turned with which tool?
Crescent wrench
If a tang appears to be stuck, do not apply too much pressure. If the tang breaks off, it will be difficult to stop the flow of gas. It is recommended that who service a stuck tang?
The Gas Co.
How do you approach a stuck tang in a EMERGENCY CONDITIONS:
- 2 wrenches: 1 on the tang, other on the backing nut
- Hold tang steady, loosen backing nut ONE-QUARTER TURN ONLY!
If the backing nut is loosened to far, the core can fly out, leaking medium pressure gas, at __ to __ psi.
40 to 60 psi
Newer stopcock have a pin driven into the backing nut, and bolt, and cannot be loosened. What are some other options to unstuck a tang:
- Give backing nut a tap with non-metallic hammer, freeing the core
- Turn the tang, one-quarter turn, to stop the flow of gas; half-turn will continue to let the gas flow
- Tighten backing nut to lock the core in the “OFF” position
What is a larger version of a residential stopcock? It is used on high-pressure risers and piping, at industrial/commercial sites, and comes in various sizes to fit different diameter pipes.
Nordstrom Valve
The tang on a Nordstrom valve can only be turned how, in either direction, ensuring the “ON” and “OFF” positions are easy to locate.
One-Quarter Turn
Some industrial meters are equipped with a gate valve that has a wheel handle (similar to an OS&Y), turning the handle in which direction several revolutions will shut off the gas
Clockwise
What valves can be installed in addition to stopcock at public assembly occupancies, normally located near the property line, by a sidewalk.
They are 2 to3 feet underground and under a small metal, concrete or fiberglass lid; with “Gas Company” markings in raised letters.
Curb Valves- also referred to as an Emergency Shutoff Valve
To gain access to a curb valve, lift the lid with a common utility tool, screwdriver, in the hole. If the lid is stuck, and additional leverage is necessary, insert the point of a what in the hole and apply proper leverage.
Pickhead Axed
The curb valve has what type of handle to it and which direction do you turn it to stop the flow of gas?
“Faucet” type handle, turn CLOCKWISE
If the curb valve is too deep to reach with the hand, what can you use for extra reach?
Sprinkler Key
Natural gas emergencies can be divided into 3 categories:
- Inside Leak
- Outside leaks
- Leaks resulting in fires
The greatest danger results from gas leaks where, due to the potential for ignition and explosion
Inside structures
What is the first priority upon arrival on the scene of a reported leaking natural gas incident?
Safety
If a heavy odor of “gas” occurs, expect what?
The worst
A faint whiff of “gas” or a leak, which has “come and
gone” for the past few days, may allow more leeway to perform a
Leak examination
For faint gas odors, the first action is to check what?
Condition of pilot lights
If a leak is suspected, pouring what over the suspected area can confirm its presence?
Soapy water
Multi-meter service is often present in multiple-tenant occupancies, such as apartment houses, or shopping centers. Each tenant has a meter and stopcock. Additionally, where the service pipe comes through the slab, prior to the MSA’s, there will be a “master” valve called
isolation valve stopcock; which stops the flow to all tenants in the building on the service pipe
if there is a major leak and difficulty is experienced in determining which meter controls the appropriate apartment, the what provides the fastest means of control.
Main service stopcock
What are some tactical considerations at an inside leak incident?
- Determine necessity and extent of evacuation
- Remove all sources of ignition, don’t operate electrical switches
- Avoid walking on carpets in dry weather, prevent sparks from static electricity
- Turn off appliance valve
- Open windows after all sources of ignition have been eliminated
- Search for occupants who may be overcome by gas
In a natural gas incident, if the structure is determined to be unsafe to enter the structure, consider what?
Turn off gas at the meter
Spot apparatus in safe zones
Establish water supply and prepare for fire suppression ops
Outside leaks can be just as dangerous as inside leaks because gas can take the
path of least resistance, as it tries to escape to the atmosphere
Outside gas leaks who should you call?
Gas Co
Will send management representative as a liaison and spokesperson for the company
Who can shut down a transmission or distribution line?
Only the Gas Co
What is the FD role at the site of a outside leak?
Maintain public safety
Eliminating potential sources of ignition until the leak is stopped
Where do you place the apparatus at in at outside leak?
Upwind
Away from manhole covers, storm drains, or structures that can contain trapped gas
The only sure way to safely check suspected areas of a outside gas leak is to use a combustible gas indicator, can detect presence of natural gas and its lower explosive limit (LEL), who carries those?
Hazardous Materials Companies
Which method is acceptable to restrict gas flow as long as all tools used to work on plastic pipes are grounded?
Crimping plastic pipe
What can be driven into various diameter steel pipes with a rubber mallet to stop a gas leak?
Redwood plugs; it doesn’t work with polyethylene pipe
On rare occasions, pipelines may contain hazardous contaminants such as what?
Polychlorinated Biphenyls
Polychlorinated Biphenyls is what precent free from impurities?
If any liquid flows from a natural gas pipe, do not let it touch your body, treat the liquid as a hazardous material and notify who?
97%; Hazmat Co
Whenever a gas travels through piping, it can create a static electric charge on the pipe. On steel pipe, the current is drawn off and safely dissipated to the ground by the conductive pipe itself. Plastic pipe is an ____ and it is probable that the pipe will have a static charge.
Insulator
A person grabbing the pipe to apply a plug will likely discharge this current, creating spark. What can we do to prevent ignition from static electricity?
Fog down the plastic pipe with a wetting agent such as wet water
What are some considerations at a natural gas fire?
Protect exposures
Let gas burn until supply is shut off’
Control evacuation and maintain site security
Notify Gas Co
How can small fires be extinguished?
Dry chem or CO2 if necessary, to approach a shut off valve
How are larger natural gas fire extinguished?
Fog stream can be used to approach any valves
A hand-operated valve on the pipe connecting a gas appliance to a customer house line. Turning this valve will shut off gas to the appliance.
APPLIANCE VALVE
The nut on a stopcock, located opposite the tang. This nut should never be loosened except in an emergency.
Backing Nut
The cylinder inside a stopcock that allows or blocks the flow of gas. It is connected to the tang and rotated by turning the tang. It is held in place by the backing nut
CORE
The letter “G” painted or chiseled on a curb. It marks where a service line passes under the curb. It, also, indicates on which side of a structure a meter is located.
Curb marker
A small concrete compartment containing an emergency gas shutoff valve. Usually located under a sidewalk or parkway. It is accessible through a removable lid
CURB VAULT
Gas pipe within a structure, usually running inside walls and floors. It is the line from the meter to which appliances are connected.
CUSTOMER HOUSE LINE
Part of the system that carries gas from large transmission pipelines to individual customers. Sometimes referred to as a gas main. Normally, the pressure in these mains is between 40 and 60 psi
DISTRIBUTION PIPELINE SYSTEM
A gate valve, with a wheel type handle, located in a curb vault at a sidewalk or parkway. Turning the handle clockwise will shut off the gas to the structure. These valves are usually located at public assembly buildings, schools, churches, hospitals and theaters.
EMERGENCY SHUTOFF VALVE
The temperature at which ignition or explosion will occur. For natural gas it is 1100 degrees Fahrenheit. However, natural gas will only ignite when its concentration in air is between four and 14 percent
FLASH POINT
A leak in either a transmission line or distribution main. Only The Gas Company has the capability of shutting down these leaks.
HIGH PRESSURE LEAK
A toxic gas that, on rare occasions, is present in leaks at natural gas compressor stations or at underground storage fields
HYDROGEN SULFIDE
A leak in a customer house line, on the outlet side of the meter, approximately 1/3 psi. Using a redwood plug, or even by pressing a finger against the leak, can temporarily stop such leaks
LOW PRESSURE LEAK
Gas pipe running under a street or parkway; part of the distribution system
Main
The Gas Company sends a liaison to the scene of a major gas emergency that remains until the hazard is eliminated. This person will maintain communication with The Gas Company, the Fire Department, the Police Department, and the public.
MANAGEMENT REPRESENTATIVE
A meter that serves more than one unit, e.g., an apartment complex or mobile home park
Master meter
Gas from an underground leak. It may travel along pipes and rise through ground openings, or it may become concentrated in sewers and spaces under structures
MIGRATING GAS
This is the term The Gas Company uses to describe the meter and all the surrounding fittings, including the pressure regulator, the riser pipe, and the stopcock
METER SET ASSEMBLY (MSA)
A row of meters connected to a common riser. Each meter is connected to a separate customer house line. These meters can be turned off together or individually.
MULTIPLE METERS (HEADERS)
An incident involving a natural gas leak from a damaged pipeline or appliance
NATURAL GAS EMERGENCY
The type of mallet that should be used to drive a plug into the end of a broken pipe. Wooden, rubber, plastic or brass mallets will not cause an igniting spark if they strike the pipe.
NON-SPARKING MALLET
Substances known as Mercapitan and Thiophene. They have a distinct odor that is added to natural gas. Since natural gas is odorless, this substance makes it possible to identify the presence of a leak.
Odorant
An increasing number of gas distribution pipelines are made of plastic. Gas escaping from a break in these pipes can create a static electric charge. Fogging the pipe with wet water reduces this hazard.
PLASTIC PIPE
Wooden plug that is driven into a broken, low-pressure, pipe to stop the flow of gas
REDWOOD PLUG
A fixture shaped like a disc installed in the gas line, above the riser and before the meter. It reduces gas pressure to approximately 1/3 psi
Regulator
When there is a leak in a high-pressure pipeline, The Gas Company will shift the flow of gas into an alternate line. Because of the large amount of gas involved, it can take several hours for the gas to be purged from the damaged line.
Rerouting
A vertical pipe that carries natural gas from an underground service main to the MSA. It is the pipe on which the stopcock is located.
Riser
The gas line that runs under a customer’s property from the main, to the riser
Service line
A gas shutoff valve located on the riser; occasionally referred to as a “service shutoff valve”.
Stopcock
The grip on the stopcock. When its long side is turned crosswise to the riser, the flow of gas is stopped; if square, a raised line on the tang is turned crosswise when the flow of gas is stopped.
Tang
Large size pipeline, up to 36 inches in diameter, used to move gas over long distances to local distribution areas. Pressure in such a pipeline can be as high as 1,000 psi.
TRANSMISSION PIPELINE SYSTEM
Air Rescue Cushion is made of what?
Inflatable cushion composed of a larger upper cell and smaller lower cell
In the Air Rescue Cushion, how is each cell inflated?
By a separate blower through an air tube or sock
The rescue air cushion comes with what kind of electric blowers?
2 (one-half horsepower) electric blower
How can electricity for the blowers be supplied?
Variety of sources:
Truck on-board generator
Portable generator(s)
And/or
110 supply (house current)
How many Air Rescue Cushions does the department have?
24
6- 100 ft
18- 70 ft
What does the assignment to a reported “jumper” consist of?
1- BC
1- TF
1- RA
If a Air Rescue Cushion is needed at an incident, who must specifically ask for it?
The IC
What are the two situations for a “jumper” incident?
Fire or industrial accident
Suicide Victim
In a situation of a jumper incident at a fire or industrial accident, it is extremely important to communicate with the victim. The victim/s ability to responds to instructions may be limited by fear. Every attempt must be made by the rescuers to break through what and gain the cooperation of the victim.
“Fear Barrier”
In a situation at a jumper incident for a fire and industrial accident, the air rescue cushion may be deployed as a primary means of what?
Rescue or a safety backup
In the second situation, the “jumper” is a potential suicide victim. The Fire Department will work under the direction of the ______ to mitigate the emergency.
Police Department
Initial efforts should be made to communicate with the individual. While attempting to open a line of communication, rescuers should attempt to confine the jumper to:
As small an area as possible
Lateral room and depth of area must be reduced
A jumper should be “closed on” from as many sides as possible. This reduces the size of the:
Target area on the ground
In the situation of “closing in” on a jumper, rescue personnel must be aware of the potential hazard of what?
Getting too close to the “jumper”
The Air Rescue Cushion is comprised of
two cells separated by a membrane, but not completely sealed off from each other
In the rescue cushion, how can air pass between the cells?
Pass from the lower (smaller) cell to the upper (larger) cell by way of a small vent between the two
In the Air Cushion, which cell absorbs most of the energy generated by an impact?
Upper Cell
How does the upper cell absorb most if the energy?
It dissipates the energy by releasing air from the breather ports located on the side and front of the upper cell
In the air cushion, how is the amount of wire released regulated by?
An elastic cord ties over the breather ports
Tighter the cord, the less air released, thus creating a firmer cushion
In the rescue cushion, does the lower cell have a breather port?
No, very little air is released on impact from the lower cell
The lower cell on the air cushion doesn’t have breather ports which provide the lower cell with what?
Twice the energy- absorbing capability of the upper cell
In the air cushion, which cell provides the safety margin for the air pack and determines the limiting height from which a person may safely fall?
Lower cell
How fast does the Air Rescue Cushion absorb and dissipate the energy of the impact?
Less than one-sixth of a second
What is the tear strength of air cushion?
Over 50 pounds psi
What is the air cushion constructed of?
Vinyl-reinforced fabric which is fire retardant and waterproof
What are the seam of the air cushion sewn with?
Heavy-duty nylon thread (stronger than the material of the cushion)
What will happen if the air cushion is torn or punctured during an operation?
It will not seriously affect its capability
Why wont the air rescue cushion, if torn or punctured, seriously affect the capability?
- Filled with air, not sealed like a ballon
- Dual blower continually pumps air into two cells, and continually exhausts it through the breather ports
- Blowers will easily compensate for the additional loss of air
- Minor damage to the cushion might go unnoticed until it is inspected
What are the two factors the air cushion rating is based on?
- Maximum floor level which a person may fall, based on 10 feet per floor, landing on buttocks or back with a cushioning effect that is safely below the human tolerance level
- Ability of the person falling to properly hit the target
For the rescue cushion, where should the cushion be set up at during the attempted suicide?
Should be out of view
In the rescue air cushion, what is the preferred source of electricity?
On-board generator
Has the capacity to run two blowers simultaneously
Do portable generators carried by truck companies have the capacity to start two blowers at the same time?
They do not
If the on-board generator or other 110-AC power source is not available, how man portable generators will be required to deploy the Air Rescue Cushion?
Two
As a last resort what should be used to inflate the Air Rescue Cushion?
Portable Gasoline Powered Blowers
What are the two negatives to using gas powered blowers for the Air Rescue Cushion?
- Add a significant amount of noise to the scene
- Produce carbon monoxide, which causes long term degenerated effect on the vinyl-reinforced fabric of the cushion
How fast will the rescue air cushion fully inflate?
Less than 60 seconds
Where should you attach a drop bag cord to?
Eye at each corner of the cushion (pre cut, six foot length of drop cord works well)
How should a person falling into the Air Rescue Cushion should be instructed to fall?
As if they were sitting down
In a Air Rescue Cushion situation, if two people need to jump at the same time, how should they be instructed to jump?
Should hug each other tightly from the moment they jump until impact
Important they do not fall separately
In a Rescue Cushion emergency, after jumpers have landed and immediately roll off the cushion, how long shall you allow the cushion to reinflate?
20 seconds
Always have a company member observing the operation to insure that the Air Rescue Cushion is fully what?
Inflated
When rolling up the air cushion, which direction should you roll the unit?
Toward the socks
Residual air will be boarded out as the air cushion is being rolled
After the cushion is completely rolled, what should you do?
Unroll enough to fold the socks back in top the cushion and re-roll
Never store the Air Rescue Cushion while what?
Wet
Allow to dry and then fold and place on apparatus
When should the air rescue cushion be inspected?
After each use and monthly
What does the Air Rescue Cushion come with?
Repair Kit for minor cuts and tears
What should you do if there is a major damage to the air cushion?
Send in for repair
If stitchings comes apart on the air cushion, the cushion cannot be patched on a seam. Where do you send the cushion to be repaired at?
S & M
If the air cushion is in need of being cleaned, what should you use and how should you clean it?
Cold water and deck brush
Only necessary, it requires placing the cushion out of service until it has dried completely
How big is the 70 foot air cushion?
15 x 20
What is the thickness of the 70 foot air cushion?
Thickness 8’
How high does the 70 foot air cushion is rating too?
7th Floor
What is the inflation time for both the 70 and 100 foot air cushions?
One Minute
What is the re-inflation time for both the 70 and 100 foot air cushions?
20 seconds
How high is the 100 foot air cushion used for?
Rating 10th floor
How much does the 70 foot air cushion weight?
190 pounds
How much does the 100 foot air cushion weight?
360 pounds
What does the power required for the 70 foot and 100 foot air cushion?
115 V AC
What size blower is needed for the 70 foot air cushion?
Two 20”, 1/2 HP, 60 HZ
What size blower is needed for a 100 foot air cushion?
One 20”, One 24”, 1/2 HP, 60 HZ
