Cleaver-Brooks CBH 40 - Combustion Adjustment

Chapter 5-Adjustment and Maintenance
pump. It is recommended that removed pumps be
returned to the factory for complete reconditioning
rather than replacement of individual parts.
If the oil supply is below the level of the pump, a
vacuum gauge installed at the suction port of the
pump is helpful in checking the condition of the
suction line and aids in pinpointing problems. Nor-
mally a vacuum reading should not exceed 10".
Vacuums higher than this can lead to problems in
oil separation or in erratic or declining delivery.
Excessive readings can indicate restrictions such
as kinked or clogged lines, sticking or closed
valves, or even a frozen oil line. If there is no
reading look for air leaks in the lines, valve fit-
tings, or pump. On gravity fed installations a
vacuum gauge should read zero. If not, this is
evidence of restrictions being present.
If the oil supply is above the level of the pump, a
pressure gauge installed in the pump bypass port
may be used to determine that the head of oil is
not too great. If the head pressure is over 10 psi.
damage or seal leakage can occur. A pressure
reducing valve should be installed in this instance.
Seal leakage may also be caused by restrictions in
the return line.
In an initial start-up a pump noise in the form of a
whine may be noticed. This is a condition that
results from air in the oil line and should cease as
soon as the pump is able to clear the line of air. If
the condition persists after a long period of opera-
tion, it may indicate a leak in the suction line.
1-7/8"
PILOT
GAS
INLET
OIL PUMP BELT
The V -belt driving the oil pump requires no ser-
vicing and no preservatives or dressing compounds
should be used. Belts normally stretch with use
and proper tension should be maintained. Do not
apply excessive tension since this can result in
damage to the pump shaft bearings.
On a combination fired unit it is an acceptable
practice to remove the belt when gas is being used
for extended periods, although it is not absolutely
necessary to do this. If left connected, oil will
merely be circulated back to the tank. However
pump and belt life will be extended if the belt is
removed.
COMBUSTION ADJUSTMENT- OIL
Each boiler is adjusted prior to shipment from the
factory, however circumstances caused by ship-
ment, installation, or operating load conditions
may require further adjustment to assure
maximum operating efficiency and economy.
Periodic rechecks of adjustments and settings are
also recommended.
The burner system should be adjusted on the basis
of a combustion efficiency analysis after the unit
has been in operation sufficiently long to assure a
warm boiler.
Proper air-fuel ratio should be established by the
use of a combustion gas analyzer. This instrument
measures the content by percent of carbon dioxide
(C02), oxygen (02) and carbon monoxide(CO) in
SPACER
PACKING
GLAND
APPROX. 17-318" SET SO DIFFUSER
IS
FLUSH WITH END OF BURNER HSNG.
FIGURE 5-4. OIL AND GAS BURNER, GAS PILOT IGNITED, CBH 50-100
5-10