Bell & Gossett HT 205B SM Models ACA Straight Tube, Removable Bundle Heat Exchangers - Manual (Page 2)

10. Be sure the entire system is clean before starting operation to
prevent plugging of tubes with sand or refuse. The use of
strainers in settling tanks in pipe lines leading to the unit is
recommended.
11. Drain connections should not be piped to a common closed
manifold.
12. Steam hammer can cause serious damage to the tubes of any
heat exchanger. A careful consideration of the following points
before an installation is made can prevent costly repairs which
may be caused by steam hammer.
a. A vacuum breaker and/or vent, should be used in accor-
dance with the type of steam system installed.
b. The proper trap for the steam system installed should be
used.
c. The trap and the condensate return line to the trap should
be properly sized for the total capacity of the convertor.
d. The trap should be sized for the pressure at the trap, not
the inlet pressure to the steam controller.
e. Condensate should be piped and pitched to a condensate
receiver, condensate return pump or drain at an elevation
below the heat exchanger.
CAUTION: During times of shutdown, volumetric
expansion can occur. We recommend the installation
of a properly sized relief valve on both sides of the heat
exchanger.
INSTALLATION
1. Provide sufficient clearance at the stationary tube sheet end
of the unit to permit removal of tube bundles from shells. On
the packed floating tube sheet end, a space of 3 or 4 feet
should be provided to permit the removal of the rear head,
packing and retainer rings.
2. Provide valves and by-passes in the piping systems so that
both the shells and tube bundles may be by-passed to permit
cutting out the unit for inspection or repairs.
3. Provide thermometer wells and pressure gauge connections
in all piping to and from the unit and located as near the unit
as possible.
4. Provide convenient means for frequently cleaning the unit as
suggested under “Maintenance.”
5. Provide necessary air vent cocks for units so they can be
purged to prevent or relieve vapor or gas binding of either the
tube or the shell sides.
6. Foundations must be adequate so that exchangers will not
settle and cause piping strains. Foundation bolts should be
set to allow for setting inaccuracies. In concrete footings, pipe
sleeves at least one size larger than bolt diameter slipped over
the bolt and cast in place are best for this purpose, as they
allow the bolt center to be adjusted after the foundation has
set.
7. Loosen foundation bolts at one end of unit to allow free
expansion of shells. Oval holes in foundation brackets are
provided for this purpose.
8. Set exchangers level and square so that pipe connections
may be made without forcing.
9. Inspect all openings in exchanger for foreign material. Re-
move all wooden plugs and shipping pads just before
installing. Do not expose units to the elements with pads or
other covers removed from nozzles or other openings since
rain water may enter the unit and cause severe damage due
to freezing.
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