Boilout - CleaverBrooks FLX Series Operation, Service And Parts Manual

Pressure Vessel Care
If any deterioration or unusual conditions are observed,
contact your local Cleaver-Brooks authorized Representative
for recommendations.
F. BOILOUT
Any oil, grease, or other contamination found to be present on
waterside heating surfaces should be removed promptly by
boiling out the unit with an alkaline detergent solution.
Note: Before boiling out, the burner must be
ready for firing. Refer to CHAPTER 2 -
Profire EV/LNEV Burner.
There are several chemicals suitable for boilout. One
combination often used is soda ash (sodium carbonate) and
caustic soda (sodium hydroxide) at the rate of 3 to 5 pounds
each per 1,000 pounds of water, along with a small amount of
laundry detergent added as a wetting agent.
If the system is to be cleaned with the boiler, consider the
additional water content of the system in determining the
amount of chemical required. The water capacity of Cleaver-
Brooks FLX Boilers is listed in Table 3-2.
Boilout Procedure
1. Prepare the boiler for firing by taking the standard
precautions. Check for any situations that might present
a hazard.
2. Remove upper and lower drum handhole covers and
inspect all internal waterside surfaces. Remove debris
and wash all internal surfaces, including tubes. It may be
necessary to use a high pressure hose or a wash out lance
to flush out inaccessible areas. Reinstall the lower drum
handhole cover. (Use standard service gaskets during the
boilout procedure.)
3. The relief valve(s) must be removed before adding the
boilout solution so that neither the solution nor the
contaminants that it may carry can come in contact with
the valve(s). Use care in removing, handling, and
reinstalling these valves.
N o t e : F o r r e l i e f v a l v e i n s t a l l a t i o n
information, refer to Chapter 7, Section E.
"Controls."
4. Replace the regular gauge glass with a temporary gauge
glass that can be discarded after the cleaning (steam
boilers).
5. An overflow pipe should be connected to one of the top
boiler openings and routed to a safe point of discharge. A
relief valve tapping is usually used for this purpose. The
overflow connection to the boiler should incorporate a
tee fitting for adding cleaning solution to the boiler.
750-364
6. Fill the unit with clean water to a point just below the
access port in the upper drum. It is important that the
water used for the filling process is at a temperature of
70F or above.
7. Add the boilout solution using a chemical pump.
! DANGER WARNING
The chemicals used in this procedure are
corrosive to eyes and skin. Always refer to
the Material Safety Data Sheet to ensure that
t h e p r o p e r s a f e t y e q u i p m e n t a n d
precautions are present. Failure to heed this
warning could result in serious personal
injury or death.
8. Reinstall the upper handhole cover.
9. Continue to fill the boiler until it is full (indicated by flow
from the overflow connection).
10. Recheck the burner, gauge glass, pressure gauge,
feedwater supply and the position of all valves. Make
sure that all water feeding and level indicating apparatus
are in proper working condition.
11. Fire the boiler intermittently at the burners lowest fire
rate until the water reaches the boiling point. The water
should be held at this temperature for at least five hours.
Note: Do not produce pressure in the boiler.
12. Throughout the entire process, each blow-down point or
valve should be blown at least once every two hours. The
total amount of water blown from all points each time
should be approximately one-half gauge glass, this
amount being equally divided among the various manual
blowdown points and continuous blowdown system.
Blow the surface and/or continuous blow-down points
first, followed by the other blowdown points lower on
the boiler. After each blowdown cycle, the water level
should be brought back to full. If the total alkalinity in
the cleaning solution falls to a level below 3000 ppm, it
may be necessary to add additional solution, using a
chemical pump.
13. Allow a small amount of fresh water to enter the boiler in
order to create a slight overflow that will carry off
surface impurities. Continue to boil and overflow until
the water clears.
14. It is difficult to provide specific recommendations
regarding the duration of the cleaning process. In
general, a period of 18 to 36 hours will prove sufficient
to internally clean the water-side of the boiler. The
Chapter 3
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