NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
21
Model BV is available in sizes 10” to 30” and
has a 1/2” space between pipe walls. When
calculating the assembled length, allow 1”
length reduction for the overlap at each joint.
Attach the vent section directly to the draft
hood of the appliance with three (3) sheet
metal screws. Maintain the UL minimum
airspace clearance to combustibles. Where
the vent penetrates structure, use a Firestop
and the Support Assembly to maintain proper
clearance at this and successive intervals
throughout the structure.
Type B Gas Vent Connectors
Basic Vent Structure
Draft Hood connectors must be attached
to the appliance outlet with screws. Draft
Hood Connectors are available in 10” to 18”
diameters.
The accepted practice for larger diameters
(20” to 30”) is to attach a starting Length of
12” directly to the apliance flue outlet. Secure
the Length to the appliance flue outlet with a
minimum of three #8 x 1” sheet metal screws
equally spaced using the existing outer wall
lock slots as insertion point (see Fig. 32).
Draft Hood Connectors
Fig. 32
Maintain minimum airspace 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
Secure the screws until the head of the
screws are flush with the outer casing (see
Fig. 33). Penetrating through the inner wall
is acceptable only at this point to secure to
the appliance flue outlet.
Fig. 33
The Firestop Support Plate (FSP) is designed
to be used with Type B Gas Vents in diameters
of 10” to 30”. The Vent Pipe Hanger (SBA) is
designed for use with 10” and 12” diameters
only. They are used to provide lateral and
some vertical support for sections of vent, as
well as the correct clearance to combustible
materials. They also provide support and
resupport for offsets and horizontal runs. In
addition, field fabricated supports may be
used. Consult local building codes for rules
regarding field fabricated supports.
Firestop Support Plate (FSP)
Each Firestop Support Plate is designed
to support up to 30 feet of Vent Pipe when
installed as follows.
1. It is recommended that the vent pipe be
supported at least every other floor. The
distance between supports must not, in any
case, exceed 30 feet.
2. The circular cutout in the Firestop Support
Plate is designed to engage the uppermost
recess in the female end of the vent pipe
(see Fig. 34).
3. Surround the vent pipe with the two
identical Firestop Support Plate halves (see
Fig. 35). Engage the plate edges in the
uppermost recess as described in Step 2.
Use two pair of bolts and nuts to hold the
plate halves together. Four predrilled tabs
are provided for this purpose.
SUPPORT OF VENT STRUCTURE
Uppermost
Recess
Fig. 34
