Loss Of Head; Use And Maintenance; Gas Valve Adjustment - Sime RMG Manuel De L'installateur

3.4

LOSS OF HEAD

4

USE AND MAINTENANCE

4. 1 GAS VALVE
"RMG" boilers come equipped stan-
dard with a HONEYWELL VR 4605 C
gas valve (for "70 - 80" models) and
VR 4605 CB gas valve (for "90 - 100"
models). When the boiler is ignited the
first time, it is always recommended to
bleed the piping by using the pressure
outlet upstream from the valve (fig. 8).
4.2

GAS VALVE ADJUSTMENT

The "RMG" boilers have the gas valve
equipped with a coil assembly, which ena-
bles, via the double-contact regulating
thermostat, a reduction in output corre-
sponding to approx. 60% of nominal out-
put before the burner goes out comple-
tely. Calibration of the operating pressu-
res is done by SIME in the factory.
Consequently they should not be altered.
Only when you switch to another type of
gas (butane or propane) is it permitted
to alter the operating pressures ( Table
1 ). It is essential that this operation be
carried out exclusively by authorized
technical staff. When the working
pressures have been adjusted, reseal
the regulators. When the gas pressu-
res are to be reset, this must be done
following a set order: first the maximum
pressure and then the minimum.
4.2. 1 Nominal pressure adjustment
To set the maximum pressure, pro-
140
120
100
80
60
40
20
0
2.000 3.000 4.000 5.000
Flow rate in l/h
PORTATA (l/h)
TABLE 1
Methane - G20
Burner max. pressure
Burner min. pressure
Butane - G30
Burner max. pressure
Burner min. pressure
Propane - G31
Burner max. pressure
Burner min. pressure
ceed as follows (fig. 9):
– connect the pressure column or a
pressure gauge to the pressure
int ake locat ed on t he bur ner
manifold;
– unscrew the screw (4) completely;
– set the knob of the thermostat to
the maximum value;
110
100
90
80
70
6.000 7.000 8.000 10.000 11.000
9.000
RMG 70
mbar 9.3
mbar 4.5
mbar 25.2
mbar 12.2
mbar 32.6
mbar 16.4
– supply electric power to the boiler;
– loosen the locknut (1) and turn the
– tighten the locknut (1);
KEY
1 EV1 coil
2 Pressure regulator
3 Coil assembly
4 EV2 coil
5 LPG adaptor
6 Plastic cap
7 Pressure inlet upstream
8 Pressure inlet
downstream
RMG 80 RMG 90 RMG 100
9. 1 9.3 9.3
4.6 4.7 4.7
25.4 25. 1 25. 1
12.3 12.0 12.5
30.2 30.0 32.7
16. 1 15.6 16.6
connection (3):
to reduce the pressure, turn the
connection (3) counterclockwise; to
increase the pressure, turn the con-
nection (3) clockwise;
Fig. 7
Fig. 8
43