NFI gas exam reference review (updated)
questions with complete solutions
1. COAXIAL -A smaller pipe that is fixed with spacers inside a larger outer pipe
DIRECT VENT
removes combustion by products while the space between the two
pipes introduced com- bastion air to the appliance coaxial pipes may
2. COLLINEAR be rigid or flexible.
DI- RECT
VENT
-Two separate pipes, one for combustion air intake and the other for
combustion by products discharge.
-The pipes are typically flexible pipes.
3. FIRE STOP
SPAC- ER -Clearances for coaxial and collinear systems may vary.
-The fire stop provides lateral support for the vent, maintains
clearance for the penetration of floors/ceilings, and prevents unwanted
communication and airflow between building levels. - Fire stops may
4. VENT TERMINA- also be required for through the wall installations.
TION MUST BE -A fire stop may be required on both sides of the wall period the first
HOW FAR stop may include a shield that must be positioned at the top of the
ABOVE GRADE?
opening.
12" at least
5. DIRECT VENT - A combustion appliance that draws combustion air from outdoors
and has a sealed exhaust system.
-Exhaust byproducts are expelled outside as well.
6. HOW IS THE PI- By turning the pilot adjustment screw
LOT FLAME
USU- ALLY
ADJUSTED?
7. WHAT Manometer
MEASURES GAS
PRESSURE
OUTPUT OF
LP/NG?
1/
2
questions with complete solutions
1. COAXIAL -A smaller pipe that is fixed with spacers inside a larger outer pipe
DIRECT VENT
removes combustion by products while the space between the two
pipes introduced com- bastion air to the appliance coaxial pipes may
2. COLLINEAR be rigid or flexible.
DI- RECT
VENT
-Two separate pipes, one for combustion air intake and the other for
combustion by products discharge.
-The pipes are typically flexible pipes.
3. FIRE STOP
SPAC- ER -Clearances for coaxial and collinear systems may vary.
-The fire stop provides lateral support for the vent, maintains
clearance for the penetration of floors/ceilings, and prevents unwanted
communication and airflow between building levels. - Fire stops may
4. VENT TERMINA- also be required for through the wall installations.
TION MUST BE -A fire stop may be required on both sides of the wall period the first
HOW FAR stop may include a shield that must be positioned at the top of the
ABOVE GRADE?
opening.
12" at least
5. DIRECT VENT - A combustion appliance that draws combustion air from outdoors
and has a sealed exhaust system.
-Exhaust byproducts are expelled outside as well.
6. HOW IS THE PI- By turning the pilot adjustment screw
LOT FLAME
USU- ALLY
ADJUSTED?
7. WHAT Manometer
MEASURES GAS
PRESSURE
OUTPUT OF
LP/NG?
1/
2
