Man L23/30DF, Project Manual

Page: 191 / 392

Specification of water for fuel-water emulsions
Prerequisites
The water used for the fuel-water emulsion is an operating fluid that must be
carefully selected, processed (if necessary) and monitored. If this is not done,
deposits, corrosion, erosion and cavitation may occur on the fuel system
components that come into contact with the fuel-water emulsion.
Specifications
The characteristic values of the water used must be within the following limit
values:
Properties/
Characteristic
Characteristic value Unit
Water type Distillate or fresh water, free of foreign matter. -
Total hardness max. 10 ºdH*
pH value 6.5 - 8 -
Chloride ion content max. 50 mg/l
Table 1: Fuel-water emulsion - characteristic values to be observed
*) 1º dH (German hard-
ness)
≙
10 mg CaO
in 1 litre of water
≙
17.9 mg CaCO
3
/l
≙
0.357 mval/l
≙
0.179 mmol/l
The MAN Diesel water testing kit contains instruments that allow the water
characteristics referred to above (and others) to be easily determined.
Additional information
If distillate (e.g. from the fresh water generator) or fully desalinated water (ion
exchanger) is available, this should ideally be used for the fuel-water emul-
sion. These types of water are free of lime and salts.
The total hardness of the water is the combined effect of the temporary and
permanent hardness. It is largely determined by the calcium and magnesium
salts. The temporary hardness depends on the hydrocarbonate content in
the calcium and magnesium salts. The lasting (permanent) hardness is deter-
mined by the remaining calcium and magnesium salts (sulphates).
Water with hardness greater than 10°dH (German total hardness) must be
blended or softened with distillate. It is not necessary to increase the hard-
ness of extremely soft water.
Treatment with anticorrosive agents not required
Treatment with anticorrosive agents is not required and must be
omitted.
Limit values
Testing instruments
Distillate
Hardness
2014-10-28 - de
Specification of water for fuel-water emulsions
Specification of water for fuel-water emulsions
General
MAN Diesel & Turbo
010.000.023-16
D010.000.023-16-0001 EN 1 (1)