HazMat Bull No. 5 Control of City Gas

Question 1

Natural Gas is not poisonous- test show that concentrations of ____ natural gas mixed with air produces no ill effects?

Answer 1

25%.

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Question 2

Natural gas is ___ than air?

Answer 2

Lighter.

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Question 3

Natural gas when burning produces _______ heat?

Answer 3

High radiant.

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Question 4

The ignition point of natural gas is ____ degrees to ____ degrees?

Answer 4

1100-1200.

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Question 5

Natural gas emergencies can be classified into four basic situations?

Answer 5

1. Gas escaping outside.
2. Gas burning outside.
3. Gas escaping inside.
4. Gas burning inside.
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Question 6

On a natural gas leak if manpower is available ________ in the immediate area to determine whether gas is getting into buildings?

Answer 6

Check structures.

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Question 7

If natural gas is escaping inside a building, ventilate the area, starting where the gas concentration is the _______?

Answer 7

Strongest.

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Question 8

Once a gas valve of any type has been turned off for any reason, _____ back to the on position?

Answer 8

Do not turn it.

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Question 9

In certain cases, where gas is supplied at low pressure, and two or more meters are used, or the distance between the point where the service pipe passes through the building wall and the gas meter exceeds _______, an additional stopcock is located in the service pipe between the point where it passes through the building wall and the gas meter?

Answer 9

20 feet.

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Question 10

Residential installations of gas meters located on the outside building wall will normally have a service from the main underground to the base of the building wall and one stopcock on this service pipe just ahead of the meter and/or regulator. This stopcock may have the __________on it depending upon the use of the residence?

Answer 10

Pentagonal nut adapter.

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Question 11

• Turn the stopcock so that the operating lug is ______ to the gas pipe. This stops the flow of gas in the pipe?

Answer 11

Crosswise.

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Question 12

Use _______ to move the stopcock to the off position. Avoid sudden, excessive force that might break the pipe at the threaded connections?

Answer 12

Gradual pressure.

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Question 13

More than a _____ of a turn will allow gas to continue to flow?

Answer 13

1/4.

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Question 14

The fire valve has a raised operating stem inside a _____ diameter pipe?

Answer 14

2-1/2”.

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Question 15

The fire valve has a raised operating stem inside a 2-1/2” diameter pipe; which projects about ____ above grade?

Answer 15

12”.

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Question 16

The fire valve has a raised operating stem inside a 2-1/2” diameter pipe; which projects about 12” above grade The 2-1/2” diameter pipe is closed on top by a ____sided threaded nut?

Answer 16

5.

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Question 17

Remove the fire valve cap with a fire plug wrench by turning it _______. If it does not move readily, tap around the edge of the cap while applying pressure in a counter clockwise direction. After removing the cap use a fire plug wrench to turn the operating head 1/4 turn clockwise?

Answer 17

Counter clockwise.

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Question 18

Remove the fire valve cap with a fire plug wrench by turning it counter clockwise. If it does not move readily, ________. After removing the cap use a fire plug wrench to turn the operating head 1/4 turn clockwise?

Answer 18

Tap around the edge of the cap while applying pressure in a counter clockwise direction.
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Question 19

On a curb stopcock remove the stopcock box cover and turn the valve _______ with a gas stopcock wrench (Tee Handle)?

Answer 19

1/4 turn either way

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Question 20

On a curb gate valve remove the valve box top and turn the ___________clockwise until the valve resists further turning; six to twenty turns depending on the size of the valve. This type of shutoff is sometimes used in lieu of a fire valve with written approval of the D.C. Fire Marshal?

Answer 20

Hand wheel or 2” square operating head.

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Question 21

On a curb gate valve remove the valve box top and turn the hand wheel or 2” square operating head clockwise until ____________ depending on the size of the valve. This type of shutoff is sometimes used in lieu of a fire valve with written approval of the D.C. Fire Marshal?

Answer 21

The valve resists further turning; six to twenty turns.

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Question 22

On a curb gate valve remove the valve box top and turn the hand wheel or 2” square operating head clockwise until the valve resists further turning; six to twenty turns depending on the size of the valve. This type of shutoff is sometimes used in lieu of a fire valve with written approval of ________?

Answer 22

The D.C. Fire Marshal.

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Question 23

Gas valves located in ______should not be operated. These control the gas flow in gas mains and the operation of these valves by other than Gas Company personnel could create a very serious hazard?

Answer 23

Streets and alleys.

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Question 24

A red tag reading ______ must be attached to any gas valve or gas control operated by a firefighter, or Gas Company personnel. This is the signal to other companies responding that the gas is off and also that it is not to be turned on by anyone other than Gas Company personnel?

Answer 24

“Gas Off”

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Question 25

A red tag reading “GAS OFF” must be attached to any gas valve or gas control operated by a firefighter, or Gas Company personnel. This is the signal to other companies responding that the gas is off and also that it is not to be turned on by anyone other than _____?

Answer 25

Gas Company personnel.

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Question 26

Natural gas mains in the District are made from?

Answer 26

Cast Iron, Steel, Wrapped/Coated Steel, Plastic Piping.

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Question 27

Natural gas service lines in the District are made from?

Answer 27

Steel, Wrapped/Coated, Copper, Plastic Piping.

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Question 28

Natural gas system pressures for Transmission lines are?

Answer 28

60 to 300 psi.

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Question 29

Natural gas system pressures for distribution lines are?

Answer 29

1/5 to 60 psi.

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Question 30

Natural gas system pressures for low pressure lines are?

Answer 30

1/5 to 1/4 psi.

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Question 31

Washington Gas Company operates a natural gas fueling station located at?

Answer 31

1240 12th Street S.E.

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Question 32

At natural gas fueling stations Fill pressure at the outlet of the fueling nozzle is approximately _____, with emergency shutoffs located at different locations for each application

Answer 32

3000 psi.

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Question 33

Gas flowing through an open, damaged, or ruptured plastic gas line will cause a build-up of _______ on the surface of the plastic that is exposed to the atmosphere?

Answer 33

Static electricity.

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