Sime RS 10 Installer'S Instructions Download Page 5

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2.2

CHARACTERISTICS
OF FEEDWATER

IT  IS  ABSOLUTELY  ESSENTIAL  THAT
THE WATER USED FOR THE CENTRAL
HEATING  SYSTEM  SHOULD  BE  TREA-
TED IN THE FOLLOWING CASES:
–very  extensive  systems  (with  high

contents of feedwater);

–frequent addition of makeup water

into the system;

–should it be necessary to empty the

system either partially or totally.

2.3

SYSTEM FILLING

Before  proceeding  to  connecting  up
the  boiler,  you  are  recommended  to
get  air  to  circulate  in  the  piping  in
order  to  eliminate  any  foreign  bodies
that  might  be  detrimental  to  the  ope-
rating efficiency of the appliance.
Filling  must  be  done  slowly  so  as  to
allow  any  air  bubbles  to  be  bled  off
through  the  air  vents  provided  on  the
heating system.
The  pressure  of  cold  charging  of  the
system, and the pressure of pre-pres-
surization  of  the  expansion  vessel,
must correspond, or in any case must
not be less than, the height of the sta-
tic column of the system (e.g., for a sta-
tic column of 5 m, the pre-pressuriza-
tion  pressure  of  the  expansion  vessel
and  the  charging  pressure  must  cor-
respond to at least 0.5 bar).

2.4

CONNECTING UP FLUE

The  flue  for  evacuation  into  the  atmo-
sphere  of  the  products  of  combustion
from  natural  draught  appliances  must
meet all national and local regulations in
force and the following requirements:
–be gas-tight to the products of com-

bustion, waterproof and thermally
insulated;

–be built of materials suitable for

resisting over time normal mechani-
cal stresses, heat, and the action of
products of combustion and their
possible condensates;

–follow a vertical path and not pre-

sent any throttling throughout its
entire length;

–be adequately insulated to prevent

phenomena of condensation or coo-
ling of fumes, in particular if located
outside the building or in unheated
ambiences;

–be set at an adequate distance

from combustible or easily inflam-
mable material by means of an air

gap or suitable insulating material;

–have beneath the mouth of the first

smoke duct a chamber for collecting
solid  material  and  any  condensate;
the  height  of  the  chamber  must  be
at  least  500  mm.  Access  to  the
chamber  must  be  guaranteed  by
means  of  an  opening  provided  with
an air-tight metal door;

–have a circular, square, or rectangu-

lar  internal  cross  section;  in  the
case  of  square  or  rectangular  sec-
tions, the corners must be rounded
off with a radius of not less than 20
mm.  However,  hydraulically  equiva-
lent cross sections are allowed;

–be equipped with a chimney-pot at

the  top,  which  must  be  outside  the
so-called  back-flow  zone,  so  as  to
prevent  the  formation  of  back-flow,
which  prevents  free  discharge  of
the products of combustion into the
atmosphere;

–be devoid of mechanical means of

suction located at the top of the pipe;

–no overpressure should be present

in a chimney that passes within or
close up to inhabited rooms.

2.4.1

Sizing of flue

The  correct  sizing  of  the  flue  is  an
essential  condition  for  efficient  boiler
operation.
To determine the useful section of the
flue, it is necessary to refer to all natio-
nal and local regulations in force.
The main factors to be taken into con-
sideration  for  calculating  the  section
are  the  heat  input  of  the  boiler,  the
type  of  fuel,  the  percentage  of  CO

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 gives the specific parameters
for the boilers of the

“RS”

series.

2.5

BOILER BODY

The boiler body comes supplied assem-
bled. Where there is difficulty in gaining
access to the boiler room, the body
can be supplied in separate sections.
For assembly, proceed as follows:
– prepare the sections, cleaning the seats

of the tapered nipples with solvent;

–insert the bead of putty (fig. 2) in the

groove provided for fume tightness,
pressing lightly;

–prepare one of the two intermediate

sections having bosses with 1/2”
holes. After lubricating them with
boiled linseed oil, insert the tapered
nipples (fig. 3);

TABLE 1

Heat input

Smokes temperature

Smoke flow

°C

gr/s

RS 6