Cleaver-Brooks CBH 40 - Boil-Out of a New Unit

Chapter 2-The Pressure Vessel
indicated by chemical analysis of the boiler water.
Inspection should be made three months after
initial starting and at regular 6, 9 or 12 month in-
tervals thereafter. The frequency of further
periodic inspections will depend upon the internal
conditions found.
If any unwanted conditions are observed water
consultant or water treating company should be
contacted for recommendations.
Any sludge, mud or sediment found will have to be
flushed out. The effectiveness of the blowdown
practiced on steam boilers will be verified and
scheduling or frequency of blowdown may have to
be revised. The need for periodic draining or wash-
out will also be indicated.
Any oil or grease present on the heating surfaces
should be removed promptly by a boil-out with an
alkaline detergent solution.
NOTE: Temperature of initial fill of water for
hydrostatic tests, boil-out, or for normal
operation should be as stated in the
ASME Boiler Code.
F. BOil~OUT OF A NEW UNIT
The internal surfaces of a newly installed boiler
may have oil, grease or other protective coatings
used in manufacturing. Such coatings must be
removed since they lower the heat transfer rate
and could cause over heating of a tube. Before
boiling out procedures may begin, the burner
should be ready for firing. The operator must be
familiar with the procedure outlined under burner
operation.
Your water consultant or water treating company
will be able to recommend a cleaning or boil-out
procedure. In the event such service is unavailable
or is yet unselected, the following information may
be of assistance.
Suggested procedure for boiling out new units is as
follows:
1. Tri-sodium phosphate and caustic soda are the
suggested chemicals for cleaning of boilers.
The quantities will vary according to con-
ditions but an amount of one pound of each
chemical per 50 gallons of water is suggested.
See
chart below for boiler water capacity.
Boiler
Model
Water- Gallons
Water- Weight
and Size
Normal Flooded
Normal
Flooded
CBH 25
210
235
1750
1960
CBH 30
205 230
1710
1915
CBH 40
275
310
2290
2585
CBH 50A
- 295
- 2460
CBH 50
375
440
3125 3665
CBH 60
350
420
2920
3500
CBH 70
550
650
4625
5420
CBH 80
535
630
4460 5250
CBH
100
610
715 5085
5960
CBH lOOA
-
595
-
4960
2-6
2. When dissolving chemicals, the following
procedure is suggested. Warm water should
be put into a suitable container. Slowly in-
troduce the dry chemical into the water
stirring at all times until the chemical is com-
pletely dissolved. Add the chemical slowly
and in small amounts to prevent excessive
heat and turbulence.
Use of a suitable face mask, goggles, rubber
gloves, and protective garments is strongly
recommended when handling or mixing
caustic chemicals. Do not permit the dry
material or the concentrated solution to come
in contact with skin or clothing.
3.
An over flow pipe should be attached to one
of the top boiler openings and routed to a safe
point of discharge. A relief or safety valve
tapping is usually used.
4. Water relief valves and steam safety valves
must be removed before adding the boil-out
solution so that neither it nor the grease
which it may carry will contaminate these
valves. Use care in removing and re-installing
valves.
Refer to Section J in Chapter 5 for valve in-
stallation instructions.
5. All valves in the piping leading to or from the
system must be closed to prevent cleaning
solution from getting into the system.
6. Fill pressure vessel with clean water until top
of tubes are covered. Add the cleaning
solution and then fill to the top. The tempera-
ture of the water used in this initial fill
should be at ambient temperature.
7. The boiler should then be fired intermittently
at a low rate sufficient to hold solution just at
the boiling point. Boil the water for at least
five hours. Do not produce steam pressure.
8. Allow a small amount of fresh water to enter
boiler to create a slight overflow that will
carry off surface impurities.
9. Continue boil and overflow until water clears.
Shut burner down.
10. Let boiler cool to 120°F or less, then drain
using caution that the water is discharged
with safety.
11.
Remove hand hole plates and wash the
waterside surfaces thoroughly using a high
pressure water stream.
12. Inspect surfaces and if not clean repeat the
boil out.
13. After closing openings and reinstalling safety
or relief valves fill boiler and fire until water