Crown Boiler 24-07 - Manual (Page 51)

51
sufficiently to permit a steady trickle of water
from the surface blowoff pipe. Continue this
slow boiling and trickle of overflow for several
hours until the water coming from the overflow
is clear.
d. Stop burner and drain boiler in a manner and to
a location that hot water can be discharged with
safety.
e. Refill boiler to normal water line. If water in
gauge glass does not appear to be clear, repeat
steps (a. thru e.), and boil out the boiler for a
longer time.
2. Low pressure steam boilers such as the Series
24 should be maintained with appropriate water
treatment compounds. After cleaning process has
been completed, add water treatment compounds
as recommended by your local qualified water
treatment company.
3. Remove temporary surface blowoff piping and
replug tapping. Boil or bring water temperature to
180°F promptly in order to drive off the dissolved
gases in the fresh water.
4. If unsteady water line, foaming or priming persist,
install gate valve in Hartford Loop and drain valves
in return main and at boiler and proceed as follows:
a. Connect hoses from drain cocks to floor drain.
Close gate valve in Hartford Loop and open
drain cock in return main. Fill boiler to normal
water level, turn on burner and operate boiler
at this water level for at least 30 minutes after
the condensate begins to run hot, then turn off
burner.
Close all radiator valves. Remove all supply
main air valves and plug the openings in supply
main.
b. Draw about 5 gallons of hot water from boiler
into a container and dissolve into it appropriate
amount of a recommended boilout compound.
Remove surface blowoff plug and pour this
solution into boiler, then reinstall plug.
c. Turn on burner and keep operating while feeding
water to boiler slowly. This will raise water level
in boiler slowly so that water will be boiling hot
and will rise slowly into supply main and back
through return main, flowing from drain hose
at about 180°F. Continue until water runs clear
from drain hose for at least 30 minutes.
d. Stop feeding water to boiler but continue
operating burner until excess water in boiler
flows out through supply main and water lowers
(by steaming) until it reaches normal level in
boiler. Turn off burner. Drain boiler. Open all
radiator valves. Reinstall all supply main air
valves. Open gate valve in Hartford Loop.
e. When boiler has cooled down sufficiently (crown
sheet of sections are not too hot to touch), close
CAUTION
Probe and float type low water cutoff
devices require annual inspection and
maintenance.
4. CHECK OPERATING CONTROL on boiler
equipped with tankless heaters. With burner off,
draw hot water until burner starts, then turn off hot
water and check burner shutdown.
5. CHECK RTC CONTROL - see the Test Section in
the RTC Installation and Maintenance Manual.
K.
BOILER AND SYSTEM CLEANING - STEAM
BOILER
NOTICE
A qualified water treatment chemical
specialist should be consulted for
recommendations regarding appropriate
chemical compounds and concentrations
which are compatible with local
environmental regulations.
WARNING
Chemicals used in treating boiler water are
toxic and/or harmful. Always use protective
clothing and equipment when working
with/near chemicals. Contact local
authorities to determine if treated boiler
water can be discharged into local waste
water system.
1. Oil, greases & sediments which accumulate in a
new boiler and piping must be removed in order
to prevent an unsteady water line and carry over
of the water into the supply main above boiler.
Operate the boiler with steam in the entire system
for a few days allowing the condensate to return
to the boiler. If the condensate can temporarily be
wasted, operate boiler only for the length of time
it takes for condensate to run clear. If the latter
cannot be achieved or if the condensate is returned
to the boiler, boil out the boiler using the SURFACE
BLOWOFF connection. See Figure 40a.
a. Drain boiler until water is just visible in gauge
glass. Run temporarily 1½” pipe line from the
surface blowoff connection to an open drain or
some other location where hot water may be
discharged safely. Do not install valve in this
line.
b. Add an appropriate amount of recommended
boilout compounds.
c. Start burner and operate sufficiently to boil
the water without producing steam pressure.
Boil for about 5 hours. Open boiler feed pipe