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9
A new manhole gasket will probably be required when replacing the manhole cover. To facilitate
replacement of the manhole gasket, and cover, it will be helpful to tape the gasket to the cover with 4
pieces of adhesive tape, to avoid slippage of gasket from cover. Gasket and cover should be
centered carefully before tightening bolts, to avoid gasket leaking or blowing out.
10
Oil and tighten bolts moderately, refill tank and allow pressure to build up on tank before attempting
to fully tighten bolts, as the water pressure will help seal the gasket.
Maintenance of Tube Bundle
Inspection of Unit
Frequently and at regular intervals, observe interior
and exterior conditions of all tubes and keep them
clean.
Tube cleaning negligence may result in
complete stoppage of flow through some tube, with
consequent overheating of these tubes and
compared to surrounding tubes, resulting in severe
expansion strains and leaking tube joints.
Indication of Fouling
Tube bundles subject to fouling scaling should be
cleaned periodically. A light sludge or scale coating
on the tube greatly reduces its effectiveness. A
marked increase in pressure drop and/or reduction
in
performance
usually
necessary. (Assuming the unit has been checked
for air or vapor binding and this has been found not
to be the cause.) Since the difficulty of cleaning
increases rapidly as the scale thickens or deposit
increases, the intervals between cleaning should
not be excessive.
Access to Tubes
To clean or inspect inside of tubes, remove the cap.
CAUTION: Do not loosen heads until you are sure
all pressure is off equipment, and the unit is
drained.
Tube Bundle Removal
When removing the tube bundle from the tank for
inspection or cleaning, care should be exercised to
see it is not damage by improper handling. Tube
bundles are often of great weight, yet the tubes are
small and of relatively thin metal.
therefore, should rest on parts designed to carry it,
i.e., on the tube sheets, baffles, or support plates.
For withdrawing tube bundles from the tank, the
use of steel eye bolts which are screwed into the
tube sheet is recommended for the attachment of
the cable or other pulling devices.
inserted through the tubes, and bolted to a bearing
plate at the end of the bundle may also be used.
When steel cables are used for lifting vertical tube
bundles, the cable should be attached to the lifting
eyes where possible. An alternate method is to use
indicate
cleaning
is
The bundle,
Steel rods
steel rods as described above.
bundle has been in service for a considerable
length of time without being removed, it may be
necessary to use a hydraulic jack on the tube
sheet to get it started.
bearing plate should be inserted between jack
and tube sheet and tube ends should be
protected by means of a filler board.
Handling Tube Bundles Outside Shell
Do not handle tube bundles with hooks or other
tools, which might damage tubes.
should be moved out on cradles or skids.
Horizontal tube bundles should be lifted by
means of suitable slings. Baffles can be easily
bent and damaged by dragging a bundle over a
rough surface. Since the proper functioning of
the apparatus depends upon a close fit between
the outside of the baffle and the inside of the
shell, any damage to the baffles must be
carefully avoided.
Cleaning Procedures
1
Do not attempt to clean tubes by blowing
steam through individual tubes. This over
heats the tube and results in the same
expansion strains and leaks as for plugged
tubes.
2
Do not blow out tube bundle with air when
fluids normally handled are inflammable.
3
In cleaning a tube bundle, tube should not
be hammered on with any metallic tools. In
case it is necessary to use a scraper, care
should be exercised to see that the scraper
is not sharp enough to cut the metal of the
tubes.
Tube Rolling
To tighten a loose tube joint, use a suitable roller
type tube expander. Do not roll tubes that are not
leaking, as it needlessly thins and work hardens
the tube wall.
ACE BOILER INC.
Page 15
If the tube
A good-sized steel
Bundles
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