A.O. Smith SGS - 100, Installation & Service Manual

Page: 34 / 110

Installation
34 Instruction manual SGS
3
is
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
equivalent
for
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 SGS 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.
Appliance with parallel flue gas discharge material
The longest pipe must be used to check the maximum length. In this case, the
chimney pipe is the longest. This is 35 metres. This 35 metres is the sum of pipe
sections 1, 2, 3, 4 and 5. The length of the transition piece can be ignored. The
total number of bends used
in the flue gas discharge and air supply is 8. The
bend in the transition piece can be ignored. According to the table, 2.4 metres
per bend must be added. This brings the total pipe length to:
(2.4 x 8) + 35 = 19.2 + 35 = 54.2m.
This is less than the maximum length of 60 metres stated in the table. The
installation therefore fulfils the requirements.
SGS 80 150mm 115m 2.6m 1.6m
SGS 100 150mm 100m 2.6m 1.6m
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.
Appliance Diameter
1
Maximum
total length L
equivalent
90° bend
L
equivalent
45° bend