Cleaver-Brooks CBH 40 - Cleaning

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TYPICAL LOW WATER
CUTOFF AND PUMP
CONTROL
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A. High level of water: Feed pump
turns
off at this point. Fi II
pressure vessel initially to this
height.
B. Pump turns on when water level
reaches B. Distance A-B is
approximately 3/4 inch.
C. Low Water Cutoff Poir;>t: Burner
will shut off if water level
Iowen to this point.
D. Fint visible point of gouge glass.
FIGURE 2-3. BOILER WATER LEVEL
DETAILS (STEAM BOILER)
filtering, softening, de-mineralizing, deaerating
and pre-heating. After-treatment involves
chemical treatment of the boiler water.
Because of the variables involved, no one "boiler
compound" can be considered a "cure-all" nor is it
advisable to experiment with homemade treating
methods. Sound recommendations and their em-
ployment should be augmented by a periodic
analysis of the feedwater, boiler water, and con-
densate.
The internal or waterside surfaces of the pressure
vessel should be inspected with sufficient frequency
to determine the presence of any contamination,
accumulations of foreign matter, of corrosion
and/or pitting. If these conditions are detected the
water consultant or feedwater treating company
should be consulted for advice on corrective action.
It is recommended that a properly sized water
meter be installed in the raw water make-up line
to accurately determine the amount of raw water
admitted to the boiler (steam or hot water) to aid
the water treatment program in maintaining
Chapter 2- The Pressure Vessel
proper waterside conditions.
The general feeling exists that a hot water boiler
does not require water treatment, but this is a false
assumption. The recommendations of a reliable
water treating company or a water consultant
should be followed rigidly. Even though these units
generally operate on closed systems and blowdown
is seldom practiced, the need remains to be alert to
system water losses and a water meter is recom-
mended for water make-up lines.
E. ClEANING
Hot Water and Steam Piping
Steam and water piping systems connected to the
boiler may contain oil, grease or foreign matter.
These impurities must be removed to prevent
damage to pressure vessel heating surfaces. On a
steam system the condensate should be wasted un-
til tests show the elimination of undesirable im-
purities. During the period that condensate is
wasted, attention must be given to the treatment of
the raw water used as make up so that an accumu-
lation of unwanted materials or corrosion does not
occur. Follow the advice of your water treating
company.
On a hot water system, chemical cleaning is
generally necessary and the entire system should
be drained after treatment. Consult water treat-
ment companies for recommendations, cleaning
compounds and application procedures.
Pressure Vessel
The waterside of the pressure vessel must be kept
clean from grease, sludge and foreign material.
Such deposits, if present, will not only shorten the
life of the pressure vessel and interfere with ef-
ficient operation and functioning of control or
safety devices, but might quite possibly cause un-
necessary and expensive re-work, repairs and down
time.
The installation and operating conditions which
the boiler will be subjected to should be considered
and cleaning of the waterside of the pressure vessel
should be provided during the course of initial
start-up.
Th':! pressure vessel and the steam and return lines
or hot water piping represent, in effect, a closed
system. Although the steam and return (con-
densate) lines or the hot water piping system may
have been previously cleaned it is possible that:
1) Cleaning has been inadequate.
2) Partial or total old system is involved.
3) Conditions may prevent adequate cleaning of
piping.
The pressure vessel waterside should be inspected
on a periodic basis. This will reveal true internal
conditions and serve as a check against conditions
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