Bell & Gossett HT 320B User Manual

BELL & GOSSETT

SERVICE MANUAL

HT-320B-SM

TYPE “OF” WITH CAST IRON BONNET HEADS

TYPE “OF” WITH STEEL CHANNEL HEADS

TYPE “OE” WITH STEEL BONNET HEADS

Installation, Operation and
Maintenance Manual for

Models “OF” & “OE” Straight Tube,
Fixed Tubesheet Heat Exchangers

INSTALLER: PLEASE LEAVE THIS MANUAL FOR THE OWNER’S USE.

SAFETY
INSTRUCTION

This safety alert symbol will be used in this manual to draw
attention to safety related instructions. When used, the safety
alert symbol means ATTENTION! BECOME ALERT! YOUR

SAFETY IS INVOLVED! FAILURE TO FOLLOW THESE IN­STRUCTIONS MAY RESULT IN A SAFETY HAZARD.

© COPYRIGHT 1984, 1995

Bell & Gossett

Morton Grove, IL, U.S.A.

INSTALLATION

1. Provide sufficient clearance at each end of the heat exchanger
to permit rodding the tubes.

2. Provide valves and by-passes in the piping systems so that
both the shell and tube sides may be by-passed to permit
inspection or repair.

3. Provide thermometer well and pressure gauge connections in
all piping to and from the unit and locate 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. Re­move all thread protectors and shipping pads just before
installing. Do not expose units to the elements with pads or
other covers removed from openings since rain water may
enter the unit and cause severe damage due to freezing.

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. The trap must drain into an unpressurized condensate

return system. Condensate return lines must not be run at
an elevation above the bottom of the heat exchanger. To do
so may result in a buildup of the condensate level in the
heat exchanger, which could cause water hammer and
damaged tubes.

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.