TEMPRA 24
13
Holes Ø : 45 47 50
Ø
3.02 Restrictor
For boiler operation, the restrictor supplied with the unit must be mounted following the instructions below.
Determine the correct size of fl ue restrictor required. Before inserting the fl ue gas duct in the boiler, check that
the restrictor fi tted is correct and that it is correctly positioned (see fi g. 11).
N.B.: the diameter of the hole is
stamped on the restrictor
Boiler is fitted with Ø45
restrictor as standard
Fig. 11
Choice of restrictor:
RESTRICTOR FOR TWO PIPE SYSTEM
Total flow resistance
of flue system
Use
restrictor
size
minimum
maximum
mm
0 m
10 m
45
10 m
20 m
47
20 m
35 m
50
35 m
45 m
No restrictor
• With
concentric systems
:
- Choose correct restrictor from table below.
• With
2 pipe system:
- Calculate the total fl ow resistance of the air
and
fl ue pipes in metres (cap. 3.04.2)
- utilise the table shown below to choose the
more suitable restrictor for the fl ow resistance
calculated
RESTRICTOR FOR CONCENTRIC SYSTEM
Flue lenght up to:
Use
restrictor
size
Concentric
60/100
1 bend + 1 meter
50 mm
1 bend + 3 meters No restrictor
Concentric
80/125
1 bend + 3 meters
45 mm
1 bend + 4 meters
50 mm
1 bend + 5 meters No restrictor
