Additives For Cooling Water; Chemical Additives; Slushing Oil; Anti-Freeze Agents - MAN Diesel & Turbo L28/32H Instruction Manual

MAN Diesel & Turbo

Additives for cooling water

Required approval
Only in closed circuits
Only the additives approved by MAN Diesel and listed in the tables under the
"Approved cooling water additives" may be used.
section entitled
A cooling water additive may only be permitted for use if tested and
approved as per the latest directives of the ICE Research Association (FVV)
"Suitability test of internal combustion engine cooling fluid additives." The test
report must be obtainable on request. The relevant tests can be carried out
on request in Germany at the staatliche Materialprüfanstalt (Federal Institute
for Materials Research and Testing), Abteilung Oberflächentechnik (Surface
Technology Division), Grafenstraße 2 in D-64283 Darmstadt.
Once the cooling water additive has been tested by the FVV, the engine
must be tested in the second step before the final approval is granted.
Additives may only be used in closed circuits where no significant consump-
tion occurs, apart from leaks or evaporation losses.

Chemical additives

Sodium nitrite and sodium borate based additives etc. have a proven track
record. Galvanised iron pipes or zinc sacrificial anodes must not be used in
cooling systems. This corrosion protection is not required due to the prescri-
bed cooling water treatment and electrochemical potential reversal can occur
due to the cooling water temperatures which are normally present in engines
nowadays. If necessary, the pipes must be deplated.

Slushing oil

This additive is an emulsifiable mineral oil with added slushing ingredients. A
thin film of oil forms on the walls of the cooling system. This prevents corro-
sion without interfering with the transfer of heat and also prevents limescale
deposits on the walls of the cooling system.
The significance of emulsifiable corrosion-slushing oils is fading. Oil-based
emulsions are rarely used nowadays for environmental protection reasons
and also because stability problems are known to occur in emulsions.

Anti-freeze agents

If temperatures below the freezing point of water in the engine cannot be
excluded, an anti-freeze solution that also prevents corrosion must be added
to the cooling system or corresponding parts. Otherwise, the entire system
must be heated. (Military specification: Sy-7025).
Sufficient corrosion protection can be provided by adding the products listed
"Anti-freeze solutions with slushing properties" while
in the table entitled
observing the prescribed concentration. This concentration prevents freezing
at temperatures down to -22 °C. However, the quantity of anti-freeze solu-
tion actually required always depends on the lowest temperatures that are to
be expected at the place of use.
Anti- freezes are generally based on ethylene glycol. A suitable chemical anti-
corrosive agent must be added if the concentration of the anti-freeze solution
prescribed by the user for a specific application does not provide an appro-
priate level of corrosion protection, or if the concentration of anti-freeze solu-
tion used is lower due to less stringent frost protection requirements and
does not provide an appropriate level of corrosion protection. For information
on the compatibility of the anti-freeze solution with the anticorrosive agent
6680 3.3.7-01 EN
3.3.7
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