Ferroli F 30
13
3.02 Restrictor
For boiler operation, the restrictor supplied with the unit must be mounted following the instructions below.
Determine the correct size of flue restrictor required. Before inserting the flue gas duct in the boiler, check that
the restrictor fitted is correct and that it is correctly positioned (see fig. 13).
Holes Ø : 47 50 52
Ø
Fig. 13
Choice of restrictor:
• With
concentric pipes
: - up to 1m long + one bend, use the 52 mm restrictor.
- for flue lengths over 1 metre, use no restrictor.
• With
2 pipe system:
- Calculate the total flow resistance of the air and flue pipes in metres
(cap. 3.04.2)
- utilise the table shown below to choose the more suitable restrictor for
the flow resistance calculated
RESTRICTOR FOR TWO PIPE SYSTEM
ON FERROLI F30
Total flow resistance
of flue system
Use
restrictor
size
minimum
maximum
mm
0 m
20 m
47
m
0
20 m
35 m
50
35 m
45 m
52
45 m
50 m
no restrictor
N.B.: the diameter of the hole is stamped
on the restrictor
No restrictor is required for back
outlet fl ue
