6
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
U.S.A.:
DuraVent Model BV Type B Gas
Vents 3 through 30 inch sizes must be
installed with the required MINIMUM AIR
SPACE CLEARANCE TO COMBUSTIBLES
as stated below!
Canada:
DuraVent Model BV Type B Gas
Vents must be installed with the required
MINIMUM AIR SPACE CLEARANCE TO
COMBUSTIBLES as stated below!
These clearances are marked on all gas
carrying items. They apply to indoor or
outdoor vents whether they are horizontal or
vertical, or pass through floors, walls, roofs
or framed spaces. The appropriate clearance
should be observed to joists, studs, subfloors,
plywood, drywall, or plaster enclosures,
insulating sheathing, rafters, roofing, and
any other materials classed as combustible.
KEEP ELECTRICAL WIRES AND BUILDING
INSULATION AWAY FROM GAS VENT AND
OUT OF THE REQUIRED AIR SPACE!
Single wall materials used as vent connectors
are not permitted to be enclosed. There
is no need to enclose Model BV Gas Vent
where used as connectors under floors,
in crawl spaces and basements, or in
normally unoccupied or in inaccessible attics.
Enclosing the vertical portions of vents is
required where they pass through rooms,
halls or other occupied spaces.
NOTE: See pages 20-25 (Section 2) of these
instructions for additional information on the
installation of Large Diameter Model BV Type
B Gas Vents for diameters of 10” to 30”.
Maintain the required minimum air space
clearance to combustibles, wires, and
insulation:
1” - for 3” thru 30” installed in the U.S.A.
1” - for 3” thru 24” installed in CANADA
2” - 26” thru 30” installed in CANADA
4. AIR SUPPLY
Refer to the appliance installation instructions
and consult local building codes and/or NFPA
54 “National Fuel Gas Code” or the Canadian
Gas Installation Code CSA-B149.1.00 to
ensure compliance with required volume of
combustion air for each appliance installed.
5. VENT CLEARANCES, LOCATION AND
ENCLOSURES
DuraVent Type B Gas Vents are recommended
to be installed within the heated portion of the
structure wherever possible to reduce heat
loss which may in turn lead to poor draft and/
or condensation or/and ice problems.
thumb until it bends into the groove in the top/
outlet end of the adjacent piece), it prevents
the pipes from being disengaged unless the
tab is pried back out and dimples aligned.
NOTE: FOR JOINT METHOD ON LARGE
MODEL BV, SEE PAGE 22, SECTION 2 IN
THESE INSTRUCTIONS.
Attic Insulation
Shield
25mm (1”)
Clearance to
Combustibles
Enclosure
Support Plate
Gas Vent
Length
Draft Hood
Connector
Refer to the Fuel Gas
Codes NFPA 54 and
CSA-B149.1 for gas and
propane appliances and
the appliance’s installation
instructions for minimum
extension through the floor to
maintain connector clearance.
FIG. 2 - Typical Installation of Model BV (3” to 8”)
DuraCap
Cap
Storm
Collar
Flashing
45°/60° Elbows
Keep electrical wires and
building insulation away
from gas vent and out of
the required air space
