*Bk 29- Gas Utilities

Question 1

What is the ignition temperature of natural gas?

And it’s flammable range?

Answer 1

1. 1100 degrees

2. 4-14%

Question 2

Gas carried by service lines generally don’t exceed how much psi?

Answer 2

60psi

Gas mains normally 40 to 60 psi

Question 3

What is the gas psi reduced to at the service meter? (This is the pressure that is supplied to the inside of a home)

Answer 3

1/3psi

Question 4

Older mains that transport gas are what color and are made of what?

What color are newer pipes?

Answer 4

1. Salmon beige or orange, made of plastic

2. Yellow made of polyethylene

Question 5

A ring on a stopcock valve indicates what?

Answer 5

A branch service

Question 6

A flat washer on a stopcock valve indicates what about the service line?

Answer 6

That a plastic pipe is inserted inside an older metal pipe

Question 7

What does a band on the stopcock indicate?

Answer 7

The service line is plastic

Question 8

What can you look for at the curb to help locate which side the MSA is on?

Answer 8

The letter “G”

Question 9

To reset an earthquake valve, how much should you turn the reset button?

Answer 9

1/4 of a turn

Question 10

The _____ Valve is a shut off valve used on high-pressure risers and piping at industrial/commercial sites.

Answer 10

Nordstrom

Question 11

When dealing with a stuck tang (no pin driven in backing nut) during an emergency condition, you should loosen the backing nut how much?

Answer 11

1/4 turn only

Question 12

For a faint odor of gas inside a structure, always check the condition of the _________ as a first action.

Answer 12

Pilot light

Question 13

What must be done before operating on a gas leak with a plastic pipe to prevent a spark?

Answer 13

Fog down pipe with wet water

Question 14

Does a gas leak in a steel pipe create a huge spark potential?

Answer 14

No, the current is drawn off and safely dissipated to the ground by the conductive pipe

Question 15

Small gas leaks that have caught fire may be extinguished with _______ in order to approach the shutoff valve.

Answer 15

Dry chemical extinguisher or CO2

Question 16

For large gas leaks that have caught fire, what can you apply in order to approach the shutoff valve?

Answer 16

Fog pattern on hose line

Question 17

Transmission lines that bring in natural gas into SoCal are ___ to ___ inches in diameter.

Pressure in such a pipeline can be as high as _____ psi

Answer 17

12 to 36 inches

1000 psi

Question 18

Redwood plugs work on gas pipes made of ____ and don’t work on ones made of ____

Answer 18

Steel

Polyethylene

Question 19

In dealing with a curb valve with a “faucet” type handle and the valve is too deep to reach with the hand, a ____ can be used for extra reach.

Answer 19

Sprinkler key

Question 20

Per T.B. 49:

As a precautionary measure, any oily mist or liquid encountered in any natural gas pipeline system should be presumed to contain _____. Notify hazmat.

Answer 20

PCB’s (polychlorinated byphenyls)

Question 21

Above ground gas lines must be made of _____ and cannot be _____

Answer 21

Steel

Plastic

Question 22

_______ gas mains are normally located underneath city streets, parallel to curbs, under grassy parkways, between the curb and
sidewalk, and occasionally in alleys

Answer 22

Distribution

Question 23

Gas _____ lines run from distribution mains to structures, via an outside riser, where pressure regulators and meters are located.

Answer 23

Service

Question 24

What is the name of the shutoff valve on a riser used to stop the flow of gas to the gas meter?

Answer 24

Stopcock or service cock

Can also be called the “service shut-off valve”

Question 25

Gas utilities:

Personnel should recognize and understand that a swift-kick to an earthquake valve may possibly shut off the flow of gas, when is this a viable option?

Answer 25

only in the event of a damaged or frozen stopcock, never done in lieu of a normal shut-off procedure

Question 26

A curb valve is also referred to as an _____ Valve. These valves can be installed in addition to stopcocks and are underground ___ to ___ feet by the sidewalk

Answer 26

Emergency Shut-off

2 to 3 ft

(These valves are used for public assembly occupancies such as schools, hospitals, churches, etc.)

Question 27

Ventilation can bring gas into proper explosive mixture with air, therefore, all sources of ignition shall be _____ prior to opening any windows

Answer 27

Eliminated

Question 28

If it is determined to be unsafe to enter a structure due to a gas leak, consider what 3 things?

Answer 28

• Turn off gas at the meter.
• Spot apparatus in safe zones.
• Establish a water supply and prepare for fire suppression operations.

Question 29

The Fire Department’s role at a gas leak outside of structures is to?

Answer 29

maintain public safety

Question 30

The only sure way to safely check suspected areas of gas is to use a _____

Answer 30

combustible gas indicator

Question 31

Can the bend back method be used to stop a gas leak in small diameter lines?

Answer 31

No, There is an extremely high potential for creating a static charge that usually accompanies the increased pressure of gas flowing from the restricted opening as the pipe is bent over

Question 32

Is crimping plastic pipe acceptable?

Answer 32

Yes, Crimping plastic pipe is acceptable as long as all tools used to work on plastic pipe are grounded

Question 33

The cylinder inside a stopcock that allows or blocks the flow of gas is known as the ____

Answer 33

Core

It is connected to the tang and rotated by turning the tang. It is held in place by the backing nut.

Question 34

What toxic gas on rare occasions, is present in leaks at natural gas compressor stations or at underground storage fields?

Answer 34

Hydrogen sulfide

Question 35

The common odorant in natural gas is a _____ and _____ mix.

Answer 35

Mercapitan and thiophane