Requirements For The Coolant; Table 23: Electrochemical Series / Standard Potentials Against Hydrogen; Table 24: Requirements For The Coolant; Table 25: Special Requirements For Open And Half-Open Cooling Systems - KEB COMBIVERT F6 Instructions For Use Manual

reqUIreMeNTS FOr THe cOOLANT

5.3 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 24: Requirements for the coolant
Special requirements for open and half-open cooling systems:
Impurities
Salt concentration
Algae and myxobacte-
ria
Organic materials
Table 25: Special requirements for open and half-open cooling systems:
64
Description
Corrosion protection according to
terials in cooling systems according to
The VGB cooling water directive (VGB-R 455 P) contains instructions about com-
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. It shall have a low
total hardness (<20°d) especially carbon hardness.
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.
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.
Mechanical impurities in half-open cooling systems can be counteracted when ap-
propriate water filters are used.
The salt content can increase through evaporation at half-open systems. Thus the
water is more corrosive. Adding of fresh water and removing of process water
works against.
Algae and myxobacteria can arise caused by increased water temperature and
contact with atmospheric oxygen. The algae and myxobacteria clog the filters and
obstruct the water-flow. Biocide containing additives can avoid this. Especially at
longer OFF periods of the cooling circuit preventive maintenance is necessary.
The contamination with organic materials must be kept as small as possible, be-
cause separate slime can be caused by this
Damages at the unit which are caused by clogged, corroded heat sinks or other
obvious operating errors, leads to the loss of the warranty claims.
EN 12502-1...5, water treatment and use of ma-
VGB R 455 P