Maintenance Instruction; Removing The Tube Bundle - Ace Heating Solutions Mini-Pack Operating And Maintenance Instruction Manual

Maintenance Instruction

KEEP TUBES CLEAN: In order to maintain high efficiency, the Mini-Pack tubes should be cleaned
periodically. The frequency of cleaning the tubes depends on the characteristics of the water and the
type of installation. Contact your local water treatment company for evaluation and recommendations.
GASKETS: Tighten gaskets during start up and periodically thereafter.
corrosion of the stud bolts. It is good practice to use a new gasket each time the tube bundle or bonnet is
removed.
STUDS: Keep studs protected from corrosion with paint or oil. Keep stud bolts tight to prevent leaky
gaskets. Stud bolts will not corrode if they are kept dry and protected. Use caution in removing and
reinstalling the bonnet. The Mini-Pack must be shut down and drained before attempting removal.
Before removing the nuts, apply penetrating oil and allow it to set for a few minutes. Forcing the nut off
could cause breakage. Use a torch to heat the nut and it will come off easier. If a torch is not available,
take a cold chisel and place it across the flat of the nut and strike several sharp blows with a heavy
hammer. This should loosen the nut. If necessary, it is better to split the nut open and replace it than to
break the stud off.
CONTROLS: Under normal conditions, controls furnished with the Mini-Pack require very little service. It
is important, however, that the controls be protected from moisture. All controls should be checked
frequently to make sure that they are working properly.
RELIEF VALVE: The Mini-Pack is equipped with a lever type relief valve of "ASME" rated capacity. To
maintain the valve in good working condition, it should be manually opened once a month. The relief
valve outlet should be piped directly to an open drain and the drain checked frequently for discharge. If
the relief valve is leaking or does not operate freely it should be replaced.
HIGH LIMIT AQUASTAT: The Mini-Pack is equipped with a high limit temperature safety aquastat
designed to shut down the unit in the event the water temperature exceeds the high limit set point. The
high limit should be set 12ºF to 15qF above the desired domestic hot water outlet temperature set point.
For example, if the system is heating domestic water from 40ºF to 140qF, the high limit should be set at
~152qF. The high limit aquastat will automatically reset when the temperature drops the set differential
number of degrees. The adjustable differential should be set so that the system does not start up again
until the water temperature drops at least 5 degrees below the desired hot water outlet temperature
(typically 135qF on a 140qF system). Continuing the example, with the high limit set at 152qF, the
differential should be set at least 17, thus ensuring that the system does not start heating until the water
temperature drops 17ºF down to 135qF. Refer to the included manufacturer's data sheet for adjustment
information. Turn the high limit safety control up and down to verify proper operation.

Removing The Tube Bundle

Caution: It is recommended that you wear gloves and eye protection.
1. Shut down the unit as described in the shut down instructions.
2. After the Mini-Pack has cooled, isolate the Mini-Pack by closing off the manual valves at the
domestic water inlet and outlet locations. Drain the water remaining in the shell to a safe sewer
drain.
3. Disconnect the steam inlet line and condensate outlet line from the tube bundle bonnet.
4. Remove the nuts from the bonnet side first in order to remove the bonnet. Care must be taken
when lowering the bonnet.
5. The tube bundle can now be removed by removing the nuts holding it to the shell.
6. Caution: The tube bundle is very heavy. Care should be taken when removing it from the shell.
Approximate tube bundle, bonnet, and shell weights without base are as listed.
ACE BOILER INC.
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Leaky gaskets can cause