5. Insert replacement tube by inserting the end with
the most fins removed in the opening of one tube
sheet. Slide tube until the opposite end clears the
other tube sheet and fit the tube into the hole.
6. Insert the tube roller into tube opening up to stop,
making certain that 1/8" of tube projects beyond
the tube sheet.
7. Attach drill to tube roller, holding it straight and
level.
8. Reverse drill motor and withdraw tube roller. If
necessary wrench out by hand.
9. DO NOT apply excessive torque during rolling
operation and avoid thinning any wall of the tube
beyond 0.015".
10. Use same procedure on opposite end.
11. Apply line pressure test. Re-roll if necessary.
12. Reinstall as outlined under HEAT EXCHANGER
RE-ASSEMBLY.
Cleaning Flue Gas Passageways
Soot will clog areas behind fins and cause eventual
tube failure. Any sign of soot at base of burners or
around outer jacket indicates a need for cleaning.
1. Lift off drafthood and flue collector by removing
bolts and screws.
2. Remove "V" baffles from heat exchanger.
3. Remove burner tray.
4. Take garden hose and wash heat exchanger, mak-
ing sure soot is removed from between fins. (Avoid
excessive water against refractory).
5. Reassemble; when boiler is fired, some steam will
form from wet refractory. This is normal.
6. Correct reason for soot formation.
NOTE:
In extreme cases it may be necessary to
remove the heat exchanger completely for cleaning.
The simplest method is steam cleaning at a local car
wash. DO NOT WIRE BRUSH!
CAUTION:
Soot is combustible, so exercise
extreme care.
NOTE:
Use a 3/8" heavy duty, reversible, electric
drill or larger. Proceed to expand tube until tool starts
to grab. Approximately 1/2 to 1" of the tool shank will
be visible.
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