Flexible Vent System - UTICA BOILERS MAH-125 Installation, Operation And Maintenance Manual

6.9 Flexible Vent System

Flexible Pipe Maximum Vent Lengths
3" [80 mm] Diameter Pipe
Exhaust
Natalini
Intake
Exhaust
DuraVent
®
Intake
Exhaust
Centrotherm
Intake
Exhaust
Z-Dens
Intake
Single Wall Elbows - Equivalent Length
45° bend
90° bend
Flexible vent systems shall only be run vertical.
Note
Horizontal runs before adapting to flexible must
be rigid pipe.
• Maximum vent lengths based on equivalent straight
runs only. Include rigid pipe and fittings in overall
equivalent length calculations.
• Flexible venting installations use single wall
polypropylene to pass flue gasses to base of chimney,
then flexible venting to get them to termination at the
top.
• Combustion air is not supplied through masonry
chimney. Combustion air must be from outside using 3"
[80 mm] single wall polypropylene.
• Position boiler to use minimum of rigid single wall
polypropylene venting to the chimney.
• Follow venting manufacturer's instructions on assembly
and clearances to maintain.
• Avoid sharp bends in flexible venting.
6 - COMBUSTION AIR AND VENT PIPING
125/150 165/205
75 ft [22.8m] 50 ft [15.2m]
50 ft [15.2m] 50 ft [15.2m]
82 ft [24.9m] 50 ft [15.2m]
50 ft [15.2m] 50 ft [15.2m]
52 ft [15.8m] 50 ft [15.2m]
50 ft [15.2m] 50 ft [15.2m]
50 ft [15.2m]
NA
50 ft [15.2m]
3" [80 mm]
0.82 ft [0.25 m]
1.64 ft [0.50 m]
FIGURE 6-17 - Flexible Venting System
Flexible Vent
Rigid Vent
Combustion
Air
29
Vent Terminal
240011941 REV B, [03/31/2018]