A.O. Smith BFC Cyclone Installation, User And Service Manual page 63

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0311704_BFC_28-120_III_ENEN_V2.4, 2022-10-17
Refer to the table for the correct pipe dimensions of the C13 or a C33 parallel venting
systems.
Description
Default
Diameter flue discharge/
air inlet
Maximum length air inlet
Maximum length flue gas
outlet
L 45°-bend
equivalent
L 90°-bend
equivalent
Diameter enlargement
Diameter flue discharge/
air inlet
Maximum length air inlet
Maximum length flue gas
outlet
L 45°-bend
equivalent
L 90°-bend
equivalent
1 - When the maximum total length for the default diameter of 100 mm is insufficient,
diameter 130 mm should be used. Any diameter enlargement must be carried out on both
air inlet and flue gas outlet.
2 - When the maximum total length for the default diameter of 130 mm is insufficient,
diameter 150 mm should be used. Any diameter enlargement must be carried out on both
air inlet and flue gas outlet.
Caution
Always make sure the installation is in compliance with the requirements stated in this
table.
Caution
Use a run-off of 50 mm per meter towards the water heater.
Calculate the maximum length of the air inlet and the flue gas outlet seperately:
1. Sum the lengths of the different pipe sections without bends. Ignore the length of
the adaptor box.
2. Sum the lengths of the bends. Ignore the bend in the adapter box:
- Sum L
equivalent
- Sum L
equivalent
3. Sum the lengths of the pipe sections and the lengths of the bends to calculate the
overall length of the air inlet and the flue gas outlet.
4. Adjust the length of the air inlet and/or the flue gas outlet when the overall length
exceeds the maximum length as stated in the table.
Unit BFC 28 - 60
mm 2x100
m 55
m 55
m 1,2
m 4,6
mm 2x130
m 100
m 100
m 1,4
m 2,4
for each 45° bend.
for each 90° bend.
BFC 80 - 120
(1)
(2)
2x130
65
65
1,4
2,4
2x150
100
100
1,6
2,6
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