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6 - COMBUSTION AIR AND VENT PIPING
6.9 Coaxial Venting Instructions
Maximum equivalent flue lengths for Coaxial venting are:
Coaxial Pipe Maximum Vent Lengths
Boiler Size
125/150
160/200
Vent Size
4"/2"
[100mm/60mm]
5"/3"
[128mm/80mm]
Natalini
32.80 ft [10m]
32.80 ft [10m]
DuraVent
®
32.80 ft [10m]
32.80 ft [10m]
Centrotherm
32.80 ft [10m]
32.80 ft [10m]
Coaxial Elbows - Equivalent length
4"/2" [100mm/60mm]
45°
1.64 ft. [0.5m]
90°
3.28 ft. [1.0m]
5” / 3” [128mm/80mm]
45°
1.64 ft. [0.5m]
90°
3.28 ft. [1.0m]
NOTE: Coaxial venting can run horizontal or vertical.
•
Connect flue elbow to top of boiler and adjust direction of
elbow to desired orientation (rear, right or left).
• Measure distance from outside wall face to elbow, this
dimension will be known as 'X", add distance "Y" + 2"
(50mm) to "X" this is the total dimension of the vents. See
Figure 6.6.
• Mark dimension from above on outer intake vent. Measure
length of waste material, and transfer dimension to inner
grey flue pipe.
•
Remove waste from both vents (flue and air). Verify cut
ends are square and free from burrs. Insert flue back into
intake air vent and pass them through hole in wall.
• Check all measurements before cutting. Clearance to
combustible materials is zero when using coaxial vent
system.
• After installing venting use calibrated analyzer to verify
there is no recirculation of combustion.
• Ensure termination is positioned with slots at the bottom.
6.10 Coaxial Vent Screw Placement - See Figure 6-5
Two (2) screws shall be fastened through the outer intake pipe
behind the gaskets at equal distances, approximately 180°
apart. Note the screws used must be no larger than No. 8-1/2
sheet metal screws and must be zinc coated. The length of
the screws must be 3/4" (19.00mm).
WARNING
Asphyxiation hazard. Before securing the screws
ensure the pipe has been pushed in a minimum of
1-3/4" (45mm) into the gasketed end of the other
pipe. Failure to follow these instructions could result in
death or serious injury.
!
FIGURE 6-5 - COAXIAL SCREW PLACEMENT
1-3/4" (45mm)
3/4"
(19mm)
PN 240012363 REV. A [08/31/2018]
