pipe used as a vent connector must not pass
through any floor or ceiling.
CHIMNEY CONNECTION
In entering a passageway in a masonry or metal
chimney, the vent connector must be installed
above the extreme bottom to avoid stoppage.
Means must be employed which will prevent the
vent connector from protruding so far as to
restrict the space between its end and the
opposite wall of the chimney. A thimble
or slip joint may be used to facilitate removal of
the vent connector. The vent connector must be
firmly attached to or inserted into the thimble or
slip joint to prevent the vent connector from falling
out.
DAMPERS
Manually operated dampers must not be placed
in the vent connector. This does not exclude the
use of fixed baffles, locking quadrant dampers
which are welded in a fixed position, or automatic
vent damper (when properly installed and
interlocked with the boiler gas controls).
USE OF THIMBLES
Vent connectors made of single wall metal pipe
must not pass though any combustible wall
unless they are guarded at the point of passage
by ventilated metal thimbles not smaller than the
following: 4" larger in diameter than the vent
connector, unless there is a run of not less than 6
feet of vent connector in the open, between draft
diverter outlet and the thimble, in which case the
thimble may be 2" larger. For unlisted appliances,
or for barometric provided with barometric
dampers, the thimble must be 6 inches larger in
diameter than the vent.
SINGLE WALL METAL VENT PIPE USED TO
VENT STEAM BOILERS OPERATING OVER 50
PSIG MUST NOT PASS THOUGH WALLS OR
PARTITIONS CONSTRUCTED OF
COMBUSTIBLE MATERIAL.
1.8.9 CHIMNEY & VENT CONSTRUCTION (VERTICAL SECTION)
INSTALLATION OF FACTORY BUILT SYSTEMS
Listed gas vents and factory built chimneys must be
installed in accordance with their listings and the
manufacturer's instructions. Vents and venting
systems passing through roofs must extend through
the roof flashing, roof thimble or roof jack.
INSTALLATION OF MASONRY OR METAL
CHIMNEYS
Masonry or metal chimneys must be built in
accordance with nationally recognized building codes
and standards.
INSTALLATION OF SINGLE WALL GAS VENTS
Single wall metal pipe may be used only for runs
directly from the space in which the appliance is
located through the roof or exterior wall to the outer
air. A pipe passing though a roof must extend without
interruption though the roof flashing, roof
jack, or
thimble. Single wall metal pipe must not originate in
any unoccupied attic or concealed space. Additionally
it must not pass through any attic, inside wall,
concealed space or through any floor. Minimum
clearance must be maintained between the single wall
metal pipe and any combustible surface as outlined in
Table 1.8.9.
Summary of Contents for AB Series
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