Gas Theory Period 1 (CND) Flashcards
3 Common uses of natural gas?
Cooking, Heating & Heating Domestic Water
3 Uses for liquefied petroleum gas?
Heating, Auto. Fuel, & Feed stock for the petrochemical industry.
Name of the provincial authority over local gas installation?
Alberta Municipal Affairs
What is the name & where can you find regulations that govern gas installations?
Natural Gas & Propane installation code CAN/CSA B149.1
Max gas pressure allowed in a residential dwelling?
2 PSIG
Piping between the city gate & the buildings?
Distribution Lines
The piping between the wellhead & processor?
Production Lines
The piping between the processor & the city gate?
transmission Lines
What is the function of the CAN/CSA B149.1 Code?
To set min. standards & acceptable practices
What is the function of the bulletins & STANDATAS issued to the CAN/CSA 149.1 code?
to provide amendments & interpretation of the CAN/CSA - B149.1 in relationship to safety & installation requirements for Alberta.
What do you use to give natural gas an odour?
Mercaptan
Transmission pressures maybe as high as 1500psi, the local utility may use 3 pressure systems and they are?
Low Pressure System - 8” to 14” W.C
Intermediate Pressure System - 2psig to 80 psig
High Pressure System - 80psig to 300psig
Regulator nocks down main gas from 12-80psig to ?
7” W.C.
Gas meter is only measures in _______ not pressure & has ________ chambers in it.
Volume & 4
What must you run underground on plastic gas pipe?
Tracer wire so you can locate the gas line
Symbol for propane?
C3H8
CH4 is?
natural gas
The function of the preface section in the CAN/CSA B141.1 Code?
To supply background on CAN/CSA B149.1 Code.
The function of the Scope in the CAN/CSA B149.1 Code?
In indicates where CAN/CSA should & should not apply.
2 reasons for sulphur being removed from natural gas?
To prevent acid rain & Pipe corrosion.
What are naturally occurring products of gas wells?
Natural Gas Liquid
A burner is used in ?
All gas appliances
A device that delivers the gas & air to the combustion zone for ignition is a?
Burner
The burner in a standard storage type domestic water heat is?
Aerated, Upshot, Atmospheric Burner
A common hand held torch would be considered?
an aerated burner
the part of the mixing assembly that has the smallest diameter is?
the mixer throat
Never exceed _____% over the rating on the plate.
3%
Pressure at sea level is?
14.7 psia
Gas burner are categorized by three characteristics ?
Air Mixing, Flame Pattern & Air Supply
What product creates a main concern when incomplete combustion occurs?
Carbon monoxide
Underground piping or tubing shall not pass below____.
A foundation, wall or under a building
The specific gravity of propane liquid is?
.51
Who is responsible for the installation and maintenance of piping & equipment up the gas meter?
the gas utility
the atmosphere is made up of what percentage of nitrogen ?
79%
What is the ignition temperature of natural gas?
1200 F
True or False: natural rubber maybe used as a gasket material?
False
What does the appliance input rating represent?
the max allowable appliance gas cmsumption.
12 millivolts would read as what in volts?
,012 volts (12/1000=.012)
1 Joule of energy released in one second is equal to ?
1 watt
the unit of pressure in SI is?
The Pascal
A pipe full of water with a height of 10m will have a pressure of _____KPA at the bottom?
98kpa
How many KJ are needed to raise the temperature of 1 kilogram of H2O 1 Degree Celsius?
4.2KJ
A joint of steel piping over 2” NPS must be?
Welded
What 2 materials can be used if steel pipe is required for gas lines?
Black & Galvanized Steel.
Part of the gas piping system that conducts gas down t the appliance is called?
The Drop
What is the proper procedure to follow when connecting appliances to a newly installed piping system?
Test with air for any leaks, Purge, & then light the appliance.
The finish piping has to be tested at ?
working pressure for 10mins.
True or False: A gas meter must always be installed outside?
False
The part of the building supply piping installed to collect moisture is?
the Drip Leg.
A drip must be located at the bottom of a drip serving?
A furnace.
A lubricated main shut off is used?
Upstream of the gas meter
The diameter of a drip installed in a gas piping system shall be?
Not less than the diameter of the piping it serves or NPS 2 whichever is less.
The building supply piping is found?
Down stream of the meter or second stage regulator
3 ways to check for leaks during a pressure test?
Meter test dials, Soap & water, & An manometer
What procedure should be followed if no meter is used & the gas is being turned on for the first time?
The air should be bled out through the most remote outlet.
Specific Gravity of liquid propane?
.51
The boiling point of natural gas?
So low we do not even worry about it.
A cubic meter of gas, measured at S.T.P is at a pressure of?
101 kpa
SOOT is produced by?
lack of primary air
How much oxygen is used for combustion?
20% makes up the air used
When a fuel gas is burned completely it will make?
water
3 factors necessary for combustion?
Air, Heat & Fuel
When a substance is combined with oxygen the process is called?
oxidation
Combustion is best described as?
Rapid oxidation
A column of water 12” high will exert a pressure of ?
.434 PSIG
True or False: Standing line pressure can be taken anywhere along the line?
True
A pressure of 1 psig is equivalent to what in W.C.?
28” W.C.
True or False: Pressure has no effect on the rate of flow in a gas line?
False
Gas flow in a piping system is due to?
Pressure differences
Which of the following scales are used in a monometer?
Inches of water & Ounces per squares inch
What refers to the liquid surface in the manometer?
Meniscus
Reading taken in a line supplying propane to a kitchen range should be?
11” W.C.
The max allowable difference in operating pressure between the meter and the appliance is?
Called Pressure Drop
The main purpose of a gas burner is to ?
Mix the air & gas
Flame coming off the burner horizontal is?
An Inshot Burner
A burner with air openings into the body of the burner would be considered?
Aerated
Operation used by an aerate, atmospheric in shot burner is know as the?
Venturi Effect
The pressure inside the mixer head during operation is ?
Slightly less then atmospheric
Part of the mixing assembly that has the smallest diameter is the?
Mixer throat
The location of the venture is usually between the?
Mixer Head & Mixer Tube
The main purpose of the mixer throat?
Aid in the entrainment of the air
The primary purpose of the air shutter in an aerated type of burner is to?
regulate the flow of primary air
Propane tends to release energy at a rate of approximately ______ times that of natural gas.
2.5 times
The minimum length(depth) of a dirt pocket installed on a gas appliance is _______ inches
3”
You are called to service an appliance. The customer complains that the flame explodes every time ignition occurs. A possible cause for this problem is:
the pilot flame is too small
Regulations that govern fuel-fired equipment are a ________ responsibility.
provincial
Cooling it to ______ degrees Celsius can liquefy natural gas.
-161*C
The salt caverns that are used to store natural gas near Fort Saskatchewan are ______ m deep.
1800m
If a manometer that you purchased is said to be a direct reading measuring device then the gas being measured is:
in direct contact with the measuring liquid.
When using a U-tube manometer the meniscus of the liquid is used as the reference point. The meniscus of the liquid is the?
curve at the top of the liquid.
A comparison of a volume of a substance compared to an equal volume of water.
specific gravity
What are the characteristics of a liquid state?
Definite volume, Definite mass, Indefinite shape.
What is the density of air at STP?
0.076 lbs/ft³
What is the density and the specific gravity of water in oz/in³.
0.578 oz/in³ and 1
What does the chemical symbol CO represent?
Carbon monoxide
What is the standard atmospheric pressure boiling temperature for propane liquid?
-44ºF
What is the standard atmospheric pressure boiling temperature for Liquefied natural gas?
-258ºF
What is the standard atmospheric pressure boiling temperature for butane liquid?
32ºF
What is the flame temperature of propane?
3500˚F
What is the ignition temperature of propane?
950˚F
What is the flame temperature of Natural gas?
3350˚F
What is the ignition temperature of Natural gas?
1200˚F
True or False: The air required to completely burn the fuel is defined as excess air?
False
The gas/air mixture speed exceeds the flame speed resulting in a flame that burns too high above the burner is defined as?
Lift Off
The gas/air mixture is slower than the flame speed causing the flame to burn inside the burner, possibly at the orifice is defined as?
Flashback
Combustion that does not convert all the carbon and/or hydrogen into water vapour and/or carbon dioxide is defined as?
Incomplete combustion
Air required for the intermediate and final stages of the combustion process and is added to the flame to produce complete combustion is defined as?
Secondary air
What does the appliance output represent?
Useable heat produced by the appliance.
What does the altitude rating for an appliance indicate to the gasfitter?
It indicated elevation input certification.
What factor is used for de-rating an appliance that is to be installed above high altitude?
The factor used is De-rate 4% per 1000 feet above 4500 ft.
What does the appliance input rating represent?
The maximum allowable appliance gas consumption.
negative pressure created by the Venturi effect to entrain the primary air would be called?
Atmospheric In Shot & Up shot burner
The flame at the gas burner is changing height rapidly, (the flame bounces) is defined as?
Flame oscillation
3 basic flame type that can be produced by adjusting the primary air on an aerated burner?
Carbonizing or carburizing, Neutral, & Oxidizing
6 main factors that affect pressure drop?
1) Fittings and valves
2) Length of pipe
3) Type of pipe (material it is constructed of)
4) Initial gas pressure
5) Type of gas (specific gravity)
6) Volume of gases flowing
True or False: An increase in gas flow will result in a decrease of pressure drop
False
What two tests are done to determine pressure drop?
Standing line and operating test
True or False: Pressure drop is also referred to as pressure loss and pressure differential.
True
How would an undersized gas line be identified?
If the pressure drop exceeds one inch water column
What measurement system is used to enforce Code requirements?
Imperial
At what point does the gasfitter’s jurisdiction start in a gas supply piping system?
At the outlet of the gas meter or/and downstream of the supplier’s tank on a propane system
When may the CAN/CSA B149.1-10 Natural Gas and Propane Installation Code be applied to mobile homes?
When structural alterations made to the unit render it no longer suitable for road worthiness.
What elevation qualifies as high altitude for appliances, and what is the input reduction factor when appliances are installed above high altitude?
2000 to 4500 feet above sea level and de-rate by 10%
What is the minimum dimension for accessibility to an appliance through a passageway?
36 inches x 36 inches
What is the minimum dimension for accessibility to an appliance through an opening?
24 inches x 30 inches
What is the minimum required distance between a source of ignition on an appliance and floor level in a storage garage?
18 inches
What is the minimum required distance between a source of ignition on an appliance and floor level in a repair garage?
54 inches
Threaded Schedule 40 steel piping may be used for pressures not exceeding _____.
125 PSI
True or False: Finish piping and appliance connections shall be checked under test pressure with either a/an soap solution or a/an leak detection device?
false
True or False: When a piping system is purged outdoors, the purge point must not terminate closer than 3 feet from a building or air intake.
False
What is the maximum length of a metal connector for a range?
6ft
For a portable appliance, a hose shall not exceed 75 feet in length.
false
A hose shall not be subjected to temperatures greater than ______.
125*F
Close nipple is one that?
has none of the original wall thickness left
Type G copper can only be used on?
Above ground work
Volatile is used in reference to?
How easy gas mixes with air
In their natural states CH4 & C3H8 gases @ STP are?
Hydrocarbons
The part of the natural gas piping system the gasfitter can work on is?
Only down stream of the meter
Which of the following can be used to test natural gas piping?
Air, Nitrogen & Carbon Dioxide
Min. diameter gauge that can be used for testing gas lines?
3”
A leak on a propane cylinder valve should be located with?
An approved liquid leak detector
The most likely place to find a flammable mixture of gas if there is a substance leak is?
near the edge of the gas cloud
To control the volume of gas flow?
An oriface
A fluctuating flame on an aerated burner is most likely cause by?
Problem with the gas pressure regulator.
In Alberta, type G copper tubing can be used on?
Natural gas & Propane gas lines above ground
A malleable iron fitting in a gas piping system?
Is more flexible than a cast iron fitting.
The outlet pressure of a regulator is determined by?
The spring adjustment
An operating line pressure at the meter of 7” WC and an operating line pressure of 5.8” WC at the appliance drip pocket would mean?
That there is too much restriction in the gas supply line to the appliance.
Carbon monoxide is lethal at a concentration of?
4000ppm for 1 hr
Which of the products of good combustion is considered to be a green house gas?
CO2 (Carbon dioxide)
