A.O. Smith cyclone BFC - 80 Installation And Service Manual page 31

is
3.9.4
Instruction manual BFC
Parallel connections
The table states the maximum pipe lengths for parallel systems. The maximum
pipe length depends on the chosen diameter.
Warning
Install flue component pipe runs with a run-off of 5 mm per metre.
Table of pipe lengths
1
Appliance Diameter
BFC 80 130mm
BFC 100 130mm
BFC 80 150mm
BFC 100 150mm
1) Parallel systems with diameter of 130mm or 150mm. If the maximum total
length for a diameter of 130mm is insufficient, 150mm diameter should be
used. Any diameter enlargement must be carried out on both air supply and
flue gas discharge.
You must use the longest pipe when calculating the pipe length. For example, if
the chimney pipe is 35 metres and the air supply pipe is 32 metres, then 35
metres should be taken as the length for calculation. Next, add the L
every 90° and 45° bend to this 35 metres, in both the air supply and flue gas
discharge. The following practical example illustrates how to use the table.
Practical example of parallel flue gas discharge
Example
The figure shows a BFC 100 installation. This has to be fitted with a 35m parallel
pipe 130mm in diameter plus eight 90° bends. We need to check whether this
configuration complies with the requirements stated in the table.
Maximum L
equivalent
total length 90° bend
115m 2.4m
60m 2.4m
115m 2.6m
100m 2.6m
L
equivalent
45° bend
1.4m
1.4m
1.6m
1.6m
for
equivalent
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