NFI Gas Test questions and answers graded A+
already passed
1. Air weight is 1, NG, Propane Weight? Natural Gas .4 .to .8 or
.64
, Propane 1.52
2. What is the ignition temperature for natural gas? NG 1,150F
3. What is the ignition temperature range for propane? Propane min
920-1120F
4. You need these three things for fuel to ignite? (1) ignition temperature
=
suflcient heat (2)
flamma- bility limits =
fuel to air limits
(3)combustion ratio
= air to fuel mixture
5. Flammability Limit for NG and PG (gas to air NG 4 % -14 % gas to
ratio?)(% range) air , PG 2.15 - 9.6%
(fuel gas in mixture)
6. Fuel Combustion Ratio - Air to fuel ratio (NG and LPG)( NG 10 to 1 (air
to natural
( cubic feet of air to fuel) gas cubic feet)
LPG 24: 1
7. Name the safety odorant added? mainly mercaptan
8. Define 1 BTU Amount of energy to
raise
1 pound of water 1
degree F at sea level
1/
45
,NFI Gas Test questions and answers graded A+
already passed
9. How are appliances rated? BTUs per hour
10. What happens if the main burner orifice is incomplete burn and
underrat- ed? car- bon monoxide
11. What happens if the main burner is overrated? Too much heat
2/
45
,NFI Gas Test questions and answers graded A+
already passed
12. What the rule for derating an orifice for altitude? 4 % for each 1,000
ft of al-
titude some over 1k others
over 2k ) .
13. You do not de-rate an orifice for an unvented fireplace. Fireplace may
be subject
What is the typical unavoidable to nuisance outages or
result? frequent maintenance.
14. 1 cubic foot NG equals how many BTUs? 1,000 BTUs
15. 1 cubic foot Propane equals how many BTU's? 2.5k BTU
16. 1 cubic foot Butane equals how many BTUs? 3.2k
17. Gases are nontoxic. This health risk is that displaces all the oxygen
it does what?
18. Natural gas pressure when transported in 1,500 pounds per inch
pipes across the country? (pounds per
inch?)
19. NG pressure when entering the home is? per inch 7 to 11 inches
of
water column WC
20. One psi equals how many water columns of pressure? 28
21. NG pressure after the valve and before the main burn- 3.5 water
columns of
er? pressure
22. Above what temperature does propane vaporize? -44 F (boiling
3/
45
, NFI Gas Test questions and answers graded A+
already passed
point)
23. Propane storage tanks filled this percentage to 80%
make room for vapor expansion?
24. Propane BTUS drop as it gets colder outside
4/
45
already passed
1. Air weight is 1, NG, Propane Weight? Natural Gas .4 .to .8 or
.64
, Propane 1.52
2. What is the ignition temperature for natural gas? NG 1,150F
3. What is the ignition temperature range for propane? Propane min
920-1120F
4. You need these three things for fuel to ignite? (1) ignition temperature
=
suflcient heat (2)
flamma- bility limits =
fuel to air limits
(3)combustion ratio
= air to fuel mixture
5. Flammability Limit for NG and PG (gas to air NG 4 % -14 % gas to
ratio?)(% range) air , PG 2.15 - 9.6%
(fuel gas in mixture)
6. Fuel Combustion Ratio - Air to fuel ratio (NG and LPG)( NG 10 to 1 (air
to natural
( cubic feet of air to fuel) gas cubic feet)
LPG 24: 1
7. Name the safety odorant added? mainly mercaptan
8. Define 1 BTU Amount of energy to
raise
1 pound of water 1
degree F at sea level
1/
45
,NFI Gas Test questions and answers graded A+
already passed
9. How are appliances rated? BTUs per hour
10. What happens if the main burner orifice is incomplete burn and
underrat- ed? car- bon monoxide
11. What happens if the main burner is overrated? Too much heat
2/
45
,NFI Gas Test questions and answers graded A+
already passed
12. What the rule for derating an orifice for altitude? 4 % for each 1,000
ft of al-
titude some over 1k others
over 2k ) .
13. You do not de-rate an orifice for an unvented fireplace. Fireplace may
be subject
What is the typical unavoidable to nuisance outages or
result? frequent maintenance.
14. 1 cubic foot NG equals how many BTUs? 1,000 BTUs
15. 1 cubic foot Propane equals how many BTU's? 2.5k BTU
16. 1 cubic foot Butane equals how many BTUs? 3.2k
17. Gases are nontoxic. This health risk is that displaces all the oxygen
it does what?
18. Natural gas pressure when transported in 1,500 pounds per inch
pipes across the country? (pounds per
inch?)
19. NG pressure when entering the home is? per inch 7 to 11 inches
of
water column WC
20. One psi equals how many water columns of pressure? 28
21. NG pressure after the valve and before the main burn- 3.5 water
columns of
er? pressure
22. Above what temperature does propane vaporize? -44 F (boiling
3/
45
, NFI Gas Test questions and answers graded A+
already passed
point)
23. Propane storage tanks filled this percentage to 80%
make room for vapor expansion?
24. Propane BTUS drop as it gets colder outside
4/
45
