Ferroli Sigma 30 FF 41-267-07 Installation And Servicing Instruction page 15

2.07 Restrictor and max flue length
2.07.01 Concentric Flue system
First table below shows the maximum flue lengths available for boilers with concentric systems.
For correct calculation remember to include the reduction for bend and flue terminals listed on second table.
100 mm contentric
Maximum flue
lenght permissible
Vertical *Horizontal
Sigma 30-40-50-60 4 m
* For horizontal flueing the reduction for appliance bend are already included.
A Horizontal concentric
Fig. 34
For the determination of the restrictor, identify your flue pipe configuration (A, B
or C) and choose the correct restrictor diameter from the restrictor table below.
Restrictor pipe Sigma
configuration 30-40
L 1m Ø36
A
1m L 3m Ø39
B L 1m Ø36
L 2m Ø36
C
L 2m Ø39
Boiler is fitted as standard with Ø36 and Ø41 restrictor.
For instruction on changing restrictor refer to step 7-10 at pages 14.
Sigma
125 mm concentric
Vertical *Horizontal
3 m 5 m
B Back concentric
Fig. 35
Sigma
50-60
Ø41
Ø46
Ø41
Ø41
Ø46
100 mm
contentric Reduction for bend
back exit
100 mm concentric bend 90°
5 m 1 m
100 mm concentric bend 45°
125 mm concentric bend 90°
125 mm concentric bend 45°
Fig. 36
1 m
0,5 m
0,5 m
0,25 m
C Vertical concentric
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