Absolute Boilers 750-900-1050
58
Absolute Boilers 750-900-1050
7.3 Combustion setting and adjustment
Chart 8 Combustion Tolerance Chart
Emission
Unit
Range
Part Load (20%)
Full Load (100%)
CO
2
%
6-9.5
8.0
9.0
O
2
ppm
%
8.0-4.0
7.0
5.0
CO
2
ppm
<100
Check and correct, if necessary, the boiler for correct gas/ air ratio set-up. Checking takes place on full and part load,
adjustment takes place only on the gas valve mono block. For checking and adjusting are required: an electronic
CO
2
-gauge (on the basis of O
2) and a gas pressure gauge. Note that the opening (see fig. 23) around the measuring
probe is sealed properly during measurement. Note also that measuring the O
2 levels in the flue gas is necessary, be
-
cause direct measurement of CO
2
can lead to inaccuracies due to varying CO
2
levels in the natural gas. Connect the
gas pressure meter between measuring point PG on the underside of the gas valve mono block and measuring point
PL on the venturi (see fig. 23), ensuring the connections are gas tight.
Check CO
2
- percentage (O
2
-percentage) against table
8. If the values exceed the given tolerances, adjust according to fig. 23. Check the flame through the inspection
glass, the flame must not blow off.
