2.8.4 Engine coolant recommendation
In fluid-cooled engines, the cooling fluid must be treated and monitored to prevent engine damage.
Water quality
An important factor for treating the cooling fluid is the correct water quality.
As a rule, clear and clean fresh water, as soft as possible, complying with the following analysis
values must be used:
Feature
Value
pH value
6.5 - 8.0
Chlorine (Cl)
[mg/l]
[ppm]
max. 80
Ch Sulfate
[mg/l]
[ppm]
max. 160
Alkaline ground ions
mmol/l
2.7
Hardness
°dH
15
1°dH = 0.1783 mmol/l; alkaline ground ions = 7.147 mg/l Ca
2+
or 4.336 mg/l Mg
2+
Tab. 36 Water quality parameters for cooling water
Contact the local water utilities for information regarding water quality. If the water does not meet
the parameters above, it must be treated.
If no suitable water is available, distilled or demineralized water shall be used for preparing the
coolant. Seawater, brackish water, brines and industrial wastewater are not suitable. Salts may
promote corrosion or disruptive deposits.
Coolant quality
Within the scope of further technical development, new corrosion inhibitors/antifreeze have been
approved by the engine manufacturer.
Compared to the previously approved corrosion inhibitors/antifreeze, they feature the following ad‐
vantages:
■ Fewer deposits in the engine cooling system
■ Improved heat flow
■ Higher environmental sustainability
The coolant (cooling fluid) is treated by adding anti-freeze with corrosion protection additives on the
basis of ethylene glycol to the water.
Coolant must meet the operating instructions of the engine manufacturer KUBOTA.
➤ Do not use a corrosion inhibitor/antifreeze that has not been approved by the engine manufac‐
turer.
➤ Do not use any impermissible mixing ratios of corrosion inhibitor/antifreeze and water.
Further information See chapter 10.4.1.3 for information on preparing/mixing the coolant to be used.
2
Technical Data
2.8
Engine
No.: 901783 08 USE
Operator Manual Portable Rotary Screw Compressor
MOBILAIR M82 SIGMA CONTROL SMART
15