Propane and Natural Gas UPDATED Exam
Questions and CORRECT Answers
If an appliance cannot be converted to another fuel ex. propane to natural gas, it must be a
___ appliance - CORRECT ANSWER- "Dedicated" Appliance
The "10ft-2ft-3ft" rule is a reference to what? - CORRECT ANSWER- It means that
chimneys must be 3ft above the highest point of where it passes through, while still being 2ft
higher than any portion of roof within 10ft
How many feet must a type B or L vent terminate, at minimum, above the highest connected
appliance draft hood or flue collar? - CORRECT ANSWER- 5 feet
A gas vent (B or L) must terminate atleast ___ft above a forced air inlet located within ___ft -
CORRECT ANSWER- A gas vent (B or L) must terminate at least 3ft above a forced air inlet
located within 10ft
Two ways CSST or copper tubing can be installed inside hollow walls or partitions if it is
concealed? - CORRECT ANSWER- 1) Installed in single runs that are not rigidly secured
2) With steel striker barrier, minimum 16 gauge*, barrier extends 4"
*1.3mm or .0508" thick
What is the minimum pressure for a pressure test? - CORRECT ANSWER- 1 1/2 times max
working pressure, never less than 3 psi
What is the minimum duration for a pressure test? - CORRECT ANSWER- 10 minutes
What is the chemical formula of propane? - CORRECT ANSWER- C3H8
What is the specific gravity of liquid propane? - CORRECT ANSWER- .504
,What is the specific gravity of vapor propane? - CORRECT ANSWER- 1.50
What is the boiling point of propane? - CORRECT ANSWER- -44 F
What is the ignition temperature of propane? - CORRECT ANSWER- 920 F
What is the upper flammability limit of propane? - CORRECT ANSWER- 9.60%
What is the lower flammability limit of propane? - CORRECT ANSWER- 2.15%
What is the combustion ratio of propane? - CORRECT ANSWER- 24 to 1
How many BTU per cubic foot of propane vapor? - CORRECT ANSWER- 2488 btu
How many BTU per gallon of propane? - CORRECT ANSWER- 91,502 btu
What is the chemical formula of natural gas? - CORRECT ANSWER- CH4
What is the specific gravity of liquid natural gas? - CORRECT ANSWER- .30
What is the specific gravity of natural gas vapor? - CORRECT ANSWER- .60
What is the boiling point of natural gas? - CORRECT ANSWER- -260 F
What is the ignition temperature of natural gas? - CORRECT ANSWER- 1,150 F
What is the upper limit of natural gas? - CORRECT ANSWER- 14%
What is the lower limit of natural gas? - CORRECT ANSWER- 4%
, What is the ideal combustion ratio natural gas? - CORRECT ANSWER- 10 to 1
How many BTU per cubic foot of natural gas? - CORRECT ANSWER- 1000 btu
What is a furnace plenum? - CORRECT ANSWER- A chamber constructed of duct work
attached to inlet or outlet of furnace with one or more ducts connected to it
A drip (leg) is placed where and to collect what? - CORRECT ANSWER- A drip (leg) is
placed at the lowest point of system piping, in order to collect condensate (which can then be
removed), should not be placed where condensate could freeze
*Also at outlet of meter in some cases
Which device would turn on or off an appliance's gas supply in response to changes in
pressure, temperature, or liquid level? - CORRECT ANSWER- A limit control
Condensate separates from flue gas due to either a reduction of ___ or an increase in ___ -
CORRECT ANSWER- Condensate is created either through a reduction of temperature or an
increase in pressure
What is the difference between a type 1 and type 2 clothes dryer? - CORRECT ANSWER- A
type 1 dryer is for family living
A type 2 dryer is for business/public
What is a BTU? - CORRECT ANSWER- British Thermal Unit, quantity of heat needed to
raise 1 pound of water 1 degree fahrenheit
What are the maximum temperature and pressure in a low pressure water boiler? -
CORRECT ANSWER- A low pressure water boiler has a maximum water temperature of 250
F and pressure of 160 psi
Questions and CORRECT Answers
If an appliance cannot be converted to another fuel ex. propane to natural gas, it must be a
___ appliance - CORRECT ANSWER- "Dedicated" Appliance
The "10ft-2ft-3ft" rule is a reference to what? - CORRECT ANSWER- It means that
chimneys must be 3ft above the highest point of where it passes through, while still being 2ft
higher than any portion of roof within 10ft
How many feet must a type B or L vent terminate, at minimum, above the highest connected
appliance draft hood or flue collar? - CORRECT ANSWER- 5 feet
A gas vent (B or L) must terminate atleast ___ft above a forced air inlet located within ___ft -
CORRECT ANSWER- A gas vent (B or L) must terminate at least 3ft above a forced air inlet
located within 10ft
Two ways CSST or copper tubing can be installed inside hollow walls or partitions if it is
concealed? - CORRECT ANSWER- 1) Installed in single runs that are not rigidly secured
2) With steel striker barrier, minimum 16 gauge*, barrier extends 4"
*1.3mm or .0508" thick
What is the minimum pressure for a pressure test? - CORRECT ANSWER- 1 1/2 times max
working pressure, never less than 3 psi
What is the minimum duration for a pressure test? - CORRECT ANSWER- 10 minutes
What is the chemical formula of propane? - CORRECT ANSWER- C3H8
What is the specific gravity of liquid propane? - CORRECT ANSWER- .504
,What is the specific gravity of vapor propane? - CORRECT ANSWER- 1.50
What is the boiling point of propane? - CORRECT ANSWER- -44 F
What is the ignition temperature of propane? - CORRECT ANSWER- 920 F
What is the upper flammability limit of propane? - CORRECT ANSWER- 9.60%
What is the lower flammability limit of propane? - CORRECT ANSWER- 2.15%
What is the combustion ratio of propane? - CORRECT ANSWER- 24 to 1
How many BTU per cubic foot of propane vapor? - CORRECT ANSWER- 2488 btu
How many BTU per gallon of propane? - CORRECT ANSWER- 91,502 btu
What is the chemical formula of natural gas? - CORRECT ANSWER- CH4
What is the specific gravity of liquid natural gas? - CORRECT ANSWER- .30
What is the specific gravity of natural gas vapor? - CORRECT ANSWER- .60
What is the boiling point of natural gas? - CORRECT ANSWER- -260 F
What is the ignition temperature of natural gas? - CORRECT ANSWER- 1,150 F
What is the upper limit of natural gas? - CORRECT ANSWER- 14%
What is the lower limit of natural gas? - CORRECT ANSWER- 4%
, What is the ideal combustion ratio natural gas? - CORRECT ANSWER- 10 to 1
How many BTU per cubic foot of natural gas? - CORRECT ANSWER- 1000 btu
What is a furnace plenum? - CORRECT ANSWER- A chamber constructed of duct work
attached to inlet or outlet of furnace with one or more ducts connected to it
A drip (leg) is placed where and to collect what? - CORRECT ANSWER- A drip (leg) is
placed at the lowest point of system piping, in order to collect condensate (which can then be
removed), should not be placed where condensate could freeze
*Also at outlet of meter in some cases
Which device would turn on or off an appliance's gas supply in response to changes in
pressure, temperature, or liquid level? - CORRECT ANSWER- A limit control
Condensate separates from flue gas due to either a reduction of ___ or an increase in ___ -
CORRECT ANSWER- Condensate is created either through a reduction of temperature or an
increase in pressure
What is the difference between a type 1 and type 2 clothes dryer? - CORRECT ANSWER- A
type 1 dryer is for family living
A type 2 dryer is for business/public
What is a BTU? - CORRECT ANSWER- British Thermal Unit, quantity of heat needed to
raise 1 pound of water 1 degree fahrenheit
What are the maximum temperature and pressure in a low pressure water boiler? -
CORRECT ANSWER- A low pressure water boiler has a maximum water temperature of 250
F and pressure of 160 psi
