4
USE AND MAINTENANCE
4. 1
PRESSURE CHECK
AT GAS NOZZLES
To measure pressure at the nozzles, con-
nect the pressure gauge as shown in fig. 15.
This connection must also be used to check
maximum and minimum gas pressure, but
if the setting needs to be adjusted, follow
the indications in point 4.3. 1 .
4.2
GAS VALVE (fig. 16)
The gas valve SIT 845 SIGMA is set at two
pressure values: maximum and minimum,
corresponding, according to the type of
gas, to the values indicated in Table 4.
Maximum and minimum gas pressures are
set by SIME on the production line; you are
therefore recommended not to vary the
settings. Variation in working pressure is
allowed only in the case of a changeover
from one type of gas supply (methane) to a
different type (butane or propane).
4.3
CHANGEOVER TO A
DIFFERENT GAS (fig. 17)
This operation must be carried out by
authorised personnel and only original
Sime components may be used.
5
4
1
3
6
64
To change from methane gas to LPG and
vice versa, it is necessary to:
- Close the gas tap.
- Slide off the burner manifold (3).
- Replace the main nozzles (6) and the cop-
per washer (4) with those provided in the
kit; to carry out this operation use a fixed
size 7 spanner.
- Move the connector "MET-LPG" of the
card onto the position corresponding to
the gas used (1 fig. 11).
- To set maximum and minimum gas pres-
sure values, adhere to the indications
given in point 4.3. 1 . Apart from setting, no
TABLE 4
Max burner pressure
mbar
Gas type
25 BF TS
30 BF TS
G20 (*)
11,8
12,0
G30
28,5
28,5
G31
36,5
36,5
(*) Max burner pressure is guaranteed only when the supply pressure is at least 3 mbar more than max.
burner pressure
2
3
1
4
KEY
2
1
Modulator
2
Coils EV1-EV2
3
Pressure tapping point upstream
4
Pressure tapping point downstream
5
VENT
Modulator
Min burner pressure
current
mbar
mA
25 BF TS
130
2,0
165
4,8
165
6,3
KEY
1
Pressure tapping point downstream
2
VENT
3
Sealed chamber
4
Pressure gauge differential
other operation on the valve modulator is
necessary.
After varying the working pressure,
seal the regulators.
- On completion of the operations, apply
the plate indicating the gas adaptation,
provided in the kit, to the mantle.
PLEASE NOTE: When fitting the compo-
nents removed, replace the gas washers
and, after fitting, test the seal of all the
gas connections using soapy water or
special products, avoiding the use of open
flames.
Modulator
current
30 BF TS
mA
2, 1
0
5,0
0
6,5
0
Fig. 15
Fig. 16