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5833 275 - 04
Vitotrans 300 Installation, Operating and Service
Heat Exchangers
Service
It is recommended that two people
complete this work.
1. To isolate the heat exchanger, close the 4 isolation
valves for the heat exchanger being serviced.
2. Decouple the 4 flex pipes at the heat exchanger that
is being serviced.
3. Remove the 3 retaining nuts from the heat exchanger
support
bracket.
4. Remove the heat exchanger.
IMPORTANT
Allow to cool before servicing. See preparing for service
starting on page 53.
Note:
Check for visible leaks on the heat exchanger (double
wall only). If leakage is found, replace heat exchanger.
Note:
To remove the heat exchanger follow steps 3 and 4.
5. Reinstall in reverse order. Torque: 15 lb.ft (20 Nm).
IMPORTANT
Refer to completion of service starting on page 65.
Note:
Inspect each heat exchanger opening for flow
restrictions.
Note:
The single wall heat exchanger weight is 53 lbs. (24 Kg)
The dual wall heat exchanger weight is 98 lbs. (44.6 Kg)
Cleaning the heat exchanger
The brazed plate heat exchangers operate with high
turbulence flow, even at low flow rates. This high turbulence
keeps small particles in suspension minimizing fouling and
scaling. In some applications the fouling can be very high
(e.g. when using extremely hard water at high temperatures).
It is always possible to clean the heat exchanger by
circulating a cleaning liquid. Use a weak acid, 5% phosphoric
acid or if the exchanger is frequently cleaned, 5% oxalic
acid. Pump the cleaning liquid through the exchanger. For
optimum cleaning, the cleaning solution flow rate should be
a minimum of 1.5 times the normal flow rate preferably in a
back-flush mode. After cleaning, rinse the heat exchanger
carefully with clean water and before the final rinse use
a solution of 1-2% sodium hydroxide (NaOH) or sodium
bicarbonate (NaHCO3) to ensure all acid is neutralized.
Clean at regular intervals.
Note:
Only chemical cleaning is possible (use chemicals
which do not attack copper and stainless steel)
A commercial cleaning kit is available.
If in doubt, consult a cleaning specialist.
