Xylem Heat Exchangers User Manual
the new
Heat Transfer
standard in
Storage, Installation, Operation and Maintenance
Heat Exchangers
This bulletin has been prepared as an aid
and guide to maintenance personnel. Read it
thoroughly prior to installation of any ITT Heat
Transfer heat exchanger in order to ensure
correct installation and best performance.
NOTE: Before placing this equipment
in operation, environment and service
conditions should be checked for
compat ibility with materials of
construction. Contact your nearest ITT
Heat Transfer representative if you are
not sure what the actual materials of
construction are.
Storage
Successful performance of heat transfer
equipment, length of service and freedom
from operating difficulties are largely
dependent upon:
1. Proper thermal design.
2. Proper physical design.
3. Storage practice prior to installation.
4. Manner of installation, including design
of foundation and piping.
5. The method of operation.
6. The thoroughness and frequency
of cleaning.
7. The materials, workmanship, and tools
used in maintenance and making repairs
and replacements.
Failure to perform properly may be due
to one or more of the following:
1. Exchanger being dirty.
2. Failure to remove preservation
materials after storage.
3. Operating conditions being different
than design conditions.
4. Air or gas binding.
5. Incorrect piping connections.
6. Excessive clearances between
internal parts due to corrosion.
7. Improper application.
ITT Heat Transfer heat exchangers are protected against the elements during shipment. If
they cannot be installed and put into operation
immediately upon receipt at the jobsite,
certain precautions are necessary to prevent
deterioration during storage. Responsibility
for integrity of the heat exchangers must be
assumed by the user. ITT Heat Transfer will
not be responsible for damage, corrosion or
other deterioration of heat exchanger equipment
during transit and storage.
Good storage practices are important, considering
the high costs of repair or replacement, and the
possible delays for items which require long lead
times for manufacture. The following suggested
practices are provided solely as a convenience
to the user, who shall make his own decision on
whether to use all or any of them.
On receipt of the heat exchanger, in spect
for shipping damage to all protective
1
covers. If damage is evident, inspect for
possible contamination and replace protective covers as required. If damage is
extensive, notify the carrier immediately.
If the heat exchanger is not to be placed
in immediate service, take precautions
2
to prevent rusting or contamination.
Heat exchangers for oil service, made
of ferrous materials, may be
3
pressure-tested with oil at the factory. However, the residual oil coating
on the inside surfaces of the exchanger
does not preclude the possibility of rust
formation. Upon receipt, fill these
exchangers with appropriate oil or coat
them with a corrosion prevention compound for storage. These heat exchangers
have a large warning decal, indicating
that they should be protected with oil.
The choice of preservation of interior
surfaces during storage for other service
4
applications depends upon your system
requirements and economics. Only when
included in the original purchase order
specifications will specific preservation
be incorporated prior to shipment from
the factory.
Remove any accumulations of dirt,
water, ice or snow and wipe dry before
5
moving exchangers into indoor storage.
If unit was not filled with oil or other
preservative, open drain plugs to remove
any accumulated moisture, then reseal.
Accumulation of moisture usually
indicates rusting has already started and
remedial action should be taken.
Store under cover in a heated area, if
possible. The ideal storage environment
6
for heat exchangers and accessories
is indoors, above grade, in a dry,
low-humidity atmosphere which is
sealed to prevent entry of blowing
dust, rain or snow. Maintain tempera-
tures between 70°F and 105°F (wide
temperature swings may cause condensation and “sweating” of steel parts).
Cover windows to prevent temperature
variations caused by sunlight. Provide
thermometers and humidity indicators at
several points, and maintain atmosphere
at 40% relative humidity or lower.
In tropical climates, it may be necessary
to use trays of renewable dessicant (such
7
as silica gel), or portable dehumidifiers,
to remove moisture from the air in the
storage enclosure. Thermostatically
controlled portable heaters (vented to outdoors) may be required to maintain even
air temperatures inside the enclosure.
Inspect heat exchangers and acces-
sories frequently while they are in
8
storage. Start a log to record results
of inspections and maintenance
performed while units are in storage.
A typical log entry should include, for
each component, at least the following:
a. Date
b. Inspector’s name
c. Identification of unit or item
d. Location
e. Condition of paint or coating
f. Condition of interior
g. Is free moisture present?
h. Has dirt accumulated?
i. Corrective steps taken
2
If paint deterioration begins, as
9
evidenced by discoloration or light
rusting, consider touch-up or repainting.
If the unit is painted with our standard
shop enamel, areas of light rust may be
wire brushed and touched-up with any
good quality air-drying synthetic enamel.
Units painted with special paints (when
specified on customers’ orders) may
require special techniques for touch-up or
repair. Obtain specific information from
the paint manufacturer. Painted steel
units should never be permitted to rust
or dete riorate to a point where their
strength will be impaired. But a light
surface rusting, on steel units which will
be re-painted after installation, will not
generally cause any harm. (See Items 3
and 4 for internal surface preservation.)
If the internal preservation (Items 3 and
10
4) appears inadequate during storage,
consider additional corrosion prevention
measures and more frequent inspections.
Interiors coated with rust preventive
should be restored to good condition and
re-coated promptly if signs of rust occur.
CAUTION:
Provide fire extinguishers,
fire alarms or telephone to
protect building and equip ment against fire damage.
Be sure that the building and
storage practices meet all
local, state, and federal fire
and safety codes!
Installation Planning
On removable bundle heat exchangers,
provide sufficient clearance at the station-
1
ary end to permit the removal of the tube
bundle from the shell. On the floating
head end, provide space to permit removal
of the shell cover and floating head cover.
On fixed bundle heat exchangers, provide
sufficient clearance at one end to permit
2
removal and replacement of tubes and at
the other end provide sufficient clearance
to permit tube rolling.
Provide valves and bypasses in the
piping system so that both the shell
3
side and tube side may be bypassed to
permit isolation of the heat exchanger for
inspection, cleaning and repairs.
Provide convenient means for frequent
cleaning as suggested under maintenance.
4
Provide thermometer wells and pressure
gauge pipe taps in all piping to and from
5
the heat exchanger, located as close to the
heat exchanger as possible.
Provide necessary air vent valves for the
heat exchanger so that it can be purged to
6
prevent or relieve vapor or gas binding on
both the tube side and shell side.
Provide adequate supports for mounting
the heat exchanger so that it will not
7
settle and cause piping strains.
Foundation bolts should be set accurately. In concrete footings, pipe sleeves
at least one pipe size larger than the bolt
diameter slipped over the bolt and cast
in place are best for this purpose as they
allow the bolt centers to be adjusted
after the foundation has set.
Install proper liquid level controls
and relief valves and liquid level and
8
temperature alarms, etc.
Install gauge glasses or liquid level
alarms in all vapor or gas spaces to
9
indicate any failure occurring in the
condensate drain system and to prevent
flooding of the heat exchanger.
Install a surge drum upstream from the
heat exchanger to guard against pulsation
10
of fluids caused by pumps, compressors or
other equipment.
Do not pipe drain connections to a
common closed manifold; it makes it more
11
difficult to determine that the exchanger
has been thoroughly drained.
3
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