Man L23/30DF, Project Manual

Page: 183 / 392

Coolant system
cleaning
Summary
Remove contamination/residue from operating fluid systems, ensure/re-
establish operating reliability.
Coolant systems containing deposits or contamination prevent effective cool-
ing of parts. Contamination and deposits must be regularly eliminated.
This comprises the following:
Cleaning the system and, if required,
removal of limescale deposits,
flushing the system.
Cleaning
The coolant system must be checked for contamination at regular intervals.
Cleaning is required if the degree of contamination is high. This work should
ideally be carried out by a specialist who can provide the right cleaning
agents for the type of deposits and materials in the cooling circuit. The clean-
ing should only be carried out by the engine operator if this cannot be done
by a specialist.
Oil sludge from lubricating oil that has entered the cooling system or a high
concentration of anticorrosive agents can be removed by flushing the system
with fresh water to which some cleaning agent has been added. Suitable
cleaning agents are listed alphabetically in the table entitled Cleaning agents
for removing oil sludge. Products by other manufacturers can be used pro-
viding they have similar properties. The manufacturer's instructions for use
must be strictly observed.
Manufacturer Product Concentration Duration of cleaning procedure/temperature
Drew HDE - 777 4 – 5% 4 h at 50 – 60 °C
Nalfleet MaxiClean 2 2 – 5% 4 h at 60 °C
Unitor Aquabreak 0.05 – 0.5% 4 h at ambient temperature
Vecom Ultrasonic
Multi Cleaner
4% 12 h at 50 – 60 °C
Table 1: Cleaning agents for removing oil sludge
Lime and rust deposits can form if the water is especially hard or if the con-
centration of the anticorrosive agent is too low. A thin lime scale layer can be
left on the surface as experience has shown that this protects against corro-
sion. However, limescale deposits with a thickness of more than 0.5 mm
obstruct the transfer of heat and cause thermal overloading of the compo-
nents being cooled.
Rust that has been flushed out may have an abrasive effect on other parts of
the system, such as the sealing elements of the water pumps. Together with
the elements that are responsible for water hardness, this forms what is
known as ferrous sludge which tends to gather in areas where the flow
velocity is low.
Products that remove limescale deposits are generally suitable for removing
rust. Suitable cleaning agents are listed alphabetically in the table entitled
Cleaning agents for removing limescale and rust deposits. Products by other
manufacturers can be used providing they have similar properties. The man-
Oil sludge
Lime and rust deposits
2016-09-08 - de
Quality guidelines (conventional and Common Rail engines)
Quality guidelines (conventional and Common Rail engines)
General
MAN Diesel & Turbo
010.000.002-04
M010.000.002-04-0001 EN 1 (3)