Alternatively, where flue or air intake
lengths of up to 45m are require,
Glynwed Friatec DN70 pipe may be
used.
Both 50mm flue outlet terminal and
50mm air inlet terminal are supplied
and are illustrated in Figure 2.8.1.
Both terminals are identical. The
flue and air terminals must be fitted
to the appropriate duct using solvent
weld adhesive. If 75mm terminals
are required these can be obtained
from your Keston Boilers stockist.
Request
part
numbers
C.17.2.26.00.0
(terminals)
and
C.17.2.00.60.0 (50 to 75 adapters).
2.8.2
Maximum Lengths
The maximum lengths of both air inlet pipe and flue outlet pipe, when no bends
are used, are as detailed below.
50mm
75mm
Maximum Air Inlet Length
:
29.0 m
89.0 m
Maximum Flue Outlet Length
:
15.0 m
45.0 m
Maximum Total Flue and Air Intake Length
:
30.0 m
90.0 m
However, each bend used has an equivalent length that must be deducted from
the maximum straight length stated above. Knuckle bends must not be used.
A 92.5
o
sweep elbow is equivalent to 1.0m straight length.
Example (assuming 50mm muPVC flue and air pipework):
Air inlet uses two 92.5
o
sweep elbows. Hence, maximum length permissible (i.e.
a+b in figure
2.8.2) = 29.0m
- 1.0m - 1.0m
= 27.0m
Flue outlet
uses one 92.5
o
sweep elbow.
Hence,
maximum
length
permissible
(i.e. c+d in
figure 2.8.2) =
15.0m - 1.0 m
= 14.0m
WD536
Chapter 2 - Boiler Location
The Keston C45, C40P, C55 & C55P
Installation & Servicing Instructions
Page : 15
Flue Outlet/Air Inlet Terminals
Figure 2.8.1 : Terminals
FLUE
AIR
c
d
a
Figure 2.8.2 : Flue & Air Maximum Length Example
b
C45 or C55