The weight of the vent stack or chimney must not rest on boiler draft hood. Support must be provided in compliance with applicable codes. The boiler top and draft hood must be readily removable for maintenance and inspection. Vent pipe should be adequately sup- ported to maintain proper clearances from combustible construction.
Type "B" double wall (or equivalent vent pipe is recommended. However single wall metal vent pipe may be used as specified in the latest edition of the National Flue Gas Code ANSI Z 223.1.
10’
OR LESS
VENT CAP
2’ MIN.
2’ MIN.
5’ MIN.
Listed Cap
Listed Gas Vent
Lowest Discharge
Opening
X
12
Roof Pitch is X/12
H
Roof to Lowest
Discharge Opening
Fig.# 8191.0
WARNING: These boilers must not be connected into any portion of mechanical draft systems operating under positive pressure. To do so may cause the flue products to be discharged into the living space causing serious health injury.
For connections to gas vents or chimneys, vent installations shall be in accordance with Part 7, Venting of Equipment, of the National Fuel Gas Code, ANSI Z223.1, or applicable provisions of the local building
Roof Pitch | H (Min.) Ft. |
Flat to 6/12 | 1.0 |
6/12 to 7/12 | 1.25 |
Over 7/12 to 8/12 | 1.5 |
Over 8/12 to 9/12 | 2.0 |
Over 9/12 to 10/12 | 2.5 |
Over 10/12 to 11/12 | 3.25 |
Over 11/12 to 12/12 | 4.0 |
Over 12/12 to 14/12 | 5.0 |
Over 14/12 to 16/12 | 6.0 |
Over 16/12 to 18/12 | 7.0 |
Over 18/12 to 20/12 | 7.5 |
Over 20/12 to 21/12 | 8.0 |
codes.
COMMON VENTS
Manifolds that connect more than one boiler to a common chimney must be sized to handle the combined load.
Consult available guides for proper sizing of the manifold and the chimney.
At no time should the area be less than the area of the largest outlet.
Fig. #9001
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