geminox THI 10-35 SEP, Technical Instructions, Page: 10 / 34

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GAS CONVERSION
2 - GAS/CO
2
/CO/NO
X
FLOW CONTROL AND SERVICE PRESSURE CONTROL
Po
V
Pi
K
PL
ZE
M
-5
4-
0
1
PL
2
P_OUT
P_IN
P_IN =Network gas pressure
Natural gas H (G20) : 20 mbar,
Propane (G31) : 37 mbar.
P_OUT = Outlet gas pressure to the burner.
PL = Air pressure control (fan/gas valve)
1 = Adjust the slope of the characteristic of the air/gas ratio only
when the burner is at high rate . This setting is carried out in
the factory for natural gas type H (G20). This means that the
pressure "P_OUT" can be changed to obtain the required gas
flow . (section 2.2 - page 12 - chapter II - GAS CONVER-
SION - SERVICING MANUAL).
Screw to descrease the gas flow
2 = Adjust the parallel shift of the characteristic of the air/gas ratio
only when the burner is at low rate. This screw is pre-set in
the factory. Its setting must not be normally modified even for
changing gas. If however an adjustment is required, it may be
carried out with a low scale pressure gauge 0-10 mmCE, and
a CO2, CO analyser
To modify the setting, if it is required, take off the protection
screw, and
screw to increase the gas flow . When the ad-
justments are realized, reset the protection screw.
!
Fig. 5 P
i
= Network gas pressure
Natural gas H (G20) : 20 mbar,
Propane (G31) : 37 mbar.
P
o
= Outlet gas pressure to the burner.
PL = Air pressure control (fan/gas valve)
V = Adjust the slope of the characteristic of the air/gas ratio only
when the burner is at high rate. This setting is carried out in
the factory for natural gas type H (G20). This means that the
pressure Po can be changed to obtain the required gas flow
(section 2.2 - page 12 - chapter II - GAS CONVERSION -
SERVICING MANUAL).
Screw to increase the gas flow
K = Adjust the parallel shift of the characteristic of the air/gas ratio
only when the burner is at low rate . This screw is pre-set in
the factory. Its setting must not be normally modified even for
changing gas. If however an adjustment is required, it may be
carried out with a low scale pressure gauge 0-10 mmCE, and
a CO2, CO analyser.
Screw to increase the gas flow .
GAS VALVE
SIEMENS/LANDIS
ref : VGU87A0236
GAS VALVE
SIT
ref : 848 SIGMA
!