Requirements For The Coolant; Table 38: Electrochemical Series / Standard Potentials Against Hydrogen; Table 39: Coolant Requirements For Water Coolers - KEB COMBIVERT F6 Series Instructions For Use Manual

WATer-cOOLeD DeVIceS
Material formed ion
Chrome Cr3+
Iron Fe2+
Cadmium Cd2+
Cobald Co2+
Table 38: Electrochemical series / standard potentials against hydrogen

5.1.3 requirements for the coolant

The requirements for the coolant depend on the ambient conditions as well as the used
cooling system.
General requirements for the coolant:
requirement
Standards
VGB
Cooling water directive
Abrasive substances
Hard water
Soft water
Frost protection
Corrosion protection
Table 39: Coolant requirements for water coolers
76
Standard poten-
tial
-0.71 V
-0.44 V
-0.40 V
-0.28 V
Description
Corrosion protection according to
terials in cooling systems according to
The VGB cooling water directive
mon process technology of the cooling. Particulary the interactions between cool-
ing water and components of the cooling system are described.
Abrasive substances as used in abrasive (quartz sand), clogging the cooling circuit.
Cooling water may not cause scale deposits or loose excretions. The total hard-
ness should be between 7...20 °dH, the carbon hardness between 3...10 °dH.
Soft water (<7°dH) corrodes the material.
An appropriate antifreeze must be used for applications when the heat sink or the
coolant is exposed temperatures below zero. Use only products of one manufac-
turer for a better compatibility with other additives.
KEB recommends the antifreeze Antifrogen N from Clariant with a maximum vol-
ume content of 52 %.
Additives can be used as corrosion protection. In connection with frost protec-
tion the antifreeze must have a concentration of 20...25 Vol %, in order to avoid a
change of the additives.
Alternatively, an antifreeze / glycol with a concentration of 20% ... max. vol 52%
can be used. If antifreeze is used, the water does not need to be provided with
additional additives.
Material formed ion
Platinum Pt2+
Gold Au3+
Gold Au+
12502-1...5, water treatment and use of ma-
EN
VGB R 455 P.
(VGB R 455 P) contains instructions about com-
Standard poten-
tial
1.20 V
1.42 V
1.69 V