MACH
®
Gas Fired Boiler
34
3.11 B
URNER
A
DJUSTMENT
NOTICE! Adjustments shall only be performed by service representative specifically trained and certified
to perform maintenance on the Harsco Industrial, Patterson-Kelley MACH
®
boiler. Verify proper
operation after servicing.
See rating plate for the minimum and maximum inlet gas pressure of
the boiler. The supply pressure during main burner operation must
be greater than the minimum indicated on the rating plate. Nominal
gas supply pressure is 7” W.C. for natural gas. The gas pressure
must not exceed 14” W.C. which is the maximum allowable pressure
on the gas train components.
Each boiler is furnished with a manual
shut-off valve which has an integrated test port. This port is located
on the upstream side of the valve body for measuring supply
pressure. (Seefigure right.)
The air flow is pre-set at the factory prior to shipment. Gas flow is
dependent primarily on fan speed not upstream gas pressure. The
air/gas ratio may have to be adjusted to obtain proper combustion
readings for specific local conditions. A combustion analyzer must be used. The probe must be place in the boiler
exhaust vent immediately after the boiler. Combustion should be adjusted in accordance with Table of Combustion
Exhaust Settings.
NOTICE! For high altitude adjustments (greater than 2,000 feet above sea level), see Appendix 2 at the
end of this manual.
Fuel
Nominal
High Fire Setting
Low Fire Setting
Inlet Gas
Pressure*
% O
2
% CO
2
% O
2
% CO
2
Natural
Gas
7" W.C
5.0 + 0.2
9.0 + 0.2
5.2 + 0.2
8.8 + 0.2
Propane
11" W.C
5.0 + 0.2
10.4 + 0.3
5.2 + 0.2
10.3 + 0.3
Inlet Gas
Test Port
Table of Combustion Exhaust Settings
