57
– circular, square or rectangular internal
section; if square or rectangular, corners
must be rounded off with a radium of no
less than 20 mm; hydraulically equivalent
sections are also permitted;
– fitted with a chimneypot at its top, the
outlet of which must be outside of the so-
called reflux area to prevent formation of
counter-pressure preventing the pro-
ducts of combustion from being freely
released into the atmosphere.
The minimum heights shown in fig. 4
must be complied with;
– without mechanical intake devices at the
top of the flue;
– if the flue passes through or adjacent to
inhabited rooms, there must be no over-
pressure.
2.5.1
Flue size
The correct sizing of the flue is an essential
condition for efficient boiler operation.
The main factors to be taken into conside-
ration for calculating the section are the
heat input of the boiler, the type of fuel, the
percentage of CO2, the mass flow of smoke
at nominal load, the temperature of the
smoke, the roughness of the internal wall,
and the effect of gravity on the draught
pressure, which must take into account the
external temperature and the altitude.
Table 1
shows specific parameters pertai-
ning to
“RS Mk.II”
boilers.
2.6
BOILER BODY
The cast iron body is supplied ready assem-
bled; if it cannot enter the boiler room
assembled, it may be supplied dismantled.
Follow the instructions below to assemble
the body:
– Prepare components by cleaning the hou-
sings of the conical nipples with thinner.
– Introduce the plaster seam into the
groove provided for the flue gas seal (fig.
5).
– Prepare one of the two intermediate
heating elements with a 1/2” perfora-
ted stud, lubricating the conical nipples
with boiled linseed oil before introducing
them (fig. 5/a).
– Prepare the head, following the same
procedure, and bring it into position adja-
cent to the intermediate element. Add
only one element at a time.
– Assemble the heating elements using
the pair of tie rods supplied assembled
with their accessories, code 6050900
(fig. 6), exerting pressure on the upper
hub and on the lower hub simultaneou-
sly. In the event that the elements should
not move forward in parallel during this
operation, introduce the chisel into the
tighter part and force the two parts to
be joined into parallel. The two elements
are properly joined when their outer
edges come into contact.
– Introduce the plaster seam into the
Fig. 5
Fig. 5/a
Tetto piano
0,50 m
0,50 m
Volume
tecnico
> 5 m
≤
5 m
Colmo
> 1,50 m
≤
1,50 m
Zona di reflusso
1
,50 m
2 m min.
0,50 m
oltr
e il colmo
45
°
Tetto a 45
°
Colmo
> 1,30 m
≤
1,30 m
Zona di reflusso
0,80 m
1
,20 m min.
0,50 m
oltr
e il colmo
30
°
Tetto a 30
°
Fig. 4
TABLE 1
Thermal capacity
Flue gas temperature
Flue gas rate of flow
kW
°C
gr/s
RS 129 Mk.II
145,9
154
109,4
RS 151 Mk.II
170,0
170
111,7
RS 172 Mk.II
194,2
173
118,6
RS 194 Mk.II
218,2
153
160,8
RS 215 Mk.II
242,1
160
164,2
RS 237 Mk.II
266,0
143
206,9
RS 258 Mk.II
290,0
148
213,6
RS 279 Mk.II
313,6
154
212,5
Flat roof
30° roof
45° roof
