erensan
°
“
The Heating Engineer
”
06042007
29
•
Safety elements, outlet and return safety pipes and safety valves are
checked for proper operation.
•
The mud and residuals at bottom of liquid fuel tanks are cleaned.
•
The controls described in article on taking boiler out of operation, are
performed.
2. Hydrostatic Test
Boiler parts such as the smoke pipe, nozzle, tube-sheet should pass a
hydrostatic test under an authorized mechanical engineer’s supervision,
when replaced or every 5 years for control purposes.
For boilers under 1000kW (including 1000 Kw):
•
Close all outlets and inlets with blind flanges except one outlet/return
pipe left open.
•
Let water into the boiler from the filling/discharge tap until water
comes from the vent left open.
•
Also plug the open vent with a blind flange.
•
Pressure the boiler to 1.3 times the design pressure. Wait 20
minutes and then check for drop in pressure, leakage and
permanent form changes.
For boilers over 1000kW:
The procedures described above are applied; test pressure is
taken as 1.5 times the design pressure.
erensan
°
“
The Heating Engineer
”
06042007
30
GENERAL BOILER MALFUNCTIONS
Malfunction
Symptom
Reason
Solution
No firing
•
Burner
malfunctio
n
•
Follow burner
manufacturer
recommendations.
Dark black
smoke from
chimney
(in liquid
fuel)
•
Air excess
coefficient
is low
•
Circuit
voltage
low
•
Low fuel
quality
•
Check the fresh air
entering the boiler
room or burner air
setting.
•
Voltage drop will
cause motor
revolutions to drop
and result with a low
fuel-air mixture.
•
Get your fuel
checked.
Drumming
noise in
boiler water
compartmen
t
•
Air in
system.
•
Wiring and
installatio
n error
•
Discharge the air.
•
Check the
connections
according to the
system installation
circuit diagram.
Overheating
in boiler
water
•
Circulation
pump
malfunctio
n.
•
Thermosta
t
malfunctio
n
•
Check circulation
pump for reverse
turning.
•
Check boiler
thermometer for
proper operation.