Chimney Connection; Flue Size - REMEHA P 520-13 Technical Instructions

The high-performance features of modern boilers and their use in
specific conditions as a result of the advance in burner technology
(e.g. first-stage or low modulation range operation) lead to very low
flue gas temperatures (<160°C).

1 Flue size

Refer to applicable regulations while determining the size of the flue.
Please note that P 520 boilers have pressurised and tight furnaces
and that the pressure at the nozzle must not exceed 0 mbar, unless
special sealing precautions have been taken, for instance in order to
connect a static condenser/regenerator.

2 Chimney connection

The connection shall be removable, and offer minimum load losses,
i.e. it must be as short as possible with no sudden change in section.
Its diameter shall always be at least equal to that of the boiler outlet,
i.e. :
Ø 300 mm for 13 sections
Ø 400 mm for 14 to 20 sections
Boilers with 21 to 25 sections are supplied with a plain plate. The
maximum cut-out dimensions are 500 x 700 mm.
Fit a measuring point (Ø 10 mm hole) on the flue, in order to adjust
the burner (combustion check).
P 520 P 520-13
Ø F 350
K 49
*Dimension representing the end of the 100 mm long chimney
connection mm.
Nota : with models P 520-21, P 520-23 and P 520-25, a plain plate
which must be cut out is supplied without the 100 mm chimney
connection.
29/08/05 - 300003791-001-B
Chimney connection
P 520-15 P 520-17 P 520-19
400 400 400
-19 3 25
For this reason :
- Use flue gas pipes designed to enable the flow of condensates
which may result from such operating modes in order to prevent
damage to the chimney.
- Install a draining tee at the bottom of the chimney.
The use of a draught moderator is recommended as well.
P 520-21 P 520-23
Plain plate Plain plate
-23* -1*
Remeha P 520
P 520-25
Plain plate
21*
13