Dunkirk D247 Installation Instructions Manual page 25

VENTING SYSTEM
The vent system is a very important part of the heating
system. No boiler, however efficient its design, can perform
satisfactorily if the chimney that serves it is inadequate.
Check your chimney to make sure that it is the right size,
properly constructed, clean and in good condition to ensure
proper combustion and THAT NO HAZARD WILL
DEVELOP You must also provide enough FRESH AIR FOR
COMBUSTION. LACK OF ENOUGH OXYGEN WILL
CREATE A HAZARD. If your building is of tight construction,
it may be necessary to add a FRESH AIR DUCT to provide
the OXYGEN required (see page 6).
AT LEAST ONCE A MONTH DURING HEATING SEASON
check to see that the sections of vent pipe are secure at all
joints and fittings. There should be at least two (2) sheet
metal screws per joint.
Check to see that the vent pipe slopes at least 1/4" per foot
up from the boiler to the chimney. The vent pipe should be
securely fastened to prevent sagging.
The Vent Pipe should also be checked for any deterioration
from corrosion or any other sources. See venting
instructions on page 16.
CLEANING THE NEW STEAM BOILER
New steam boilers must be cleaned previous to or during
the first few days of use in order to ensure efficient
operation. The grease or oil used to lubricate the cutting
tools or push nipples during the erection of new piping
systems picks up sand and dirt causing a scum of fine
particles and grease to accumulate on the surface of the
water in all new boilers, The heavier particles carried in
the grease may settle to the bottom of the boiler and form
sludge. This condition, if permitted to remain in the boiler,
tends to prevent the generation of steam, produces foaming
and causes an unsteady water line. This unavoidable
accumulation of oil and grease should be removed by
blowing off the boiler as follows:
Install a surface blow-off connection of at least 11/4'
nominal pipe size in boiler using the Skimming Tee
shown on page 15. The blow-off line should extend to
within 18" of the floor or to the sewer.
a. Insert a valve in the line close to the boiler.
2. Bring the water line to the center of the outlet.
a. Raise the temperature to a point just below steaming.
b. While the burners are on, open the valve in the skim
line and then slowly feed clean water into the boiler
adjusting the inlet water so that the boiler water
remains hot.
c. Continue skimming until the water is clean.
3. Close valves in boiler feed line and skim line.
4. Bring the pressure in the boiler to about 10 Ibs.
a. Turn off the burners.
b. Open the bottom drain valve permitting all the water
to drain from boiler.
5. After the boiler has cooled-, fill and flush out several
times.
6. Fill to proper water level and ready for normal service.
NOTE: Use of soda or any alkali, vinegar or any acid is not
recommended for cleaning heating boilers because it is
difficult to completely remove them and injury may occur
after the cleaning process has been completed.
BOILER WATER TREATMENT
In closed hot water heating systems, negligible amounts
of make up water are used, and water treatment is not
required.
In steam systems where the system is tight, free from leaks,
and all the steam is returned to the boiler as condensate,
the amount of make up water is small. Again, water
treatment is not required.
On steam systems with less than 90% of the steam being
returned as condensate, or with very hard or corrosive make
up water, treatment may be desirable. Follow the
recommendations of the ASME (American Society of
Mechanical Engineers) Boiler and Pressure Vessel Code,
Section Vl, latest version.
BETWEEN HEATING SEASONS
Boilers should not be drained between heating seasons.
Boilers in closed hot water heating systems may be left as
is. Steam boilers should be entirely filled with water during
the summer months to exclude air.
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