60 | INSTALLATION, OPERATION and MAINTENANCE MANUAL
Excessive periods of operation.
Acceptable CIP solutions
The definition of an acceptable CIP solution is brief and to the point. Fouling on the
plates must be removed without damaging plates and gaskets or reducing the inherent
corrosion resistance. It is important not to decompose the passive (protective) film on
stainless steel - the film contributes to preserving the resistance of the steel to
corrosion. The following examples are for informational purposes only. Each user is
responsible for determining the best cleaning method for their situation.
Do not use any chlorine-containing agents as this will attack the heat
transfer plate.
Example of an acceptable solution for dairy applications and AISI 316 plates and
NBR gaskets:
Oils and fats are removed with a water-emulsifying oil solvent, e.g., BP-System
Cleaner.
Organics and greasy coatings are removed with Sodium Hydroxide (NaOH) -
maximum concentration 2.0% and maximum temperature 85°C (185°F).
Mineral scale deposits are removed with Nitric Acid (HN0
3
) - maximum
concentration 0.5% and maximum temperature 65°C (150°F).
Excess Nitric acid can seriously damage NBR and other rubber gaskets.
Several alternatives to Nitric Acid can be used, e.g., Phosphoric Acid up to 5%
maximum concentration and 85°C (185°F) maximum temperature. Consult SPX FLOW
to find all the alternative CIP regimes possible.
The heat exchanger must be rinsed and then thoroughly drained immediately
following CIP. Residue from CIP may cause corrosion if left in the heat
exchanger.
To determine the correct quantity of chemicals for CIP cleaning, the cleaning fluid
should be checked immediately before flushing. If the concentration is too low, <0.5%,
the plate heat exchanger is probably not clean. If the concentration is too high, >1%, the
chemical consumption can be reduced.
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