JULABO LH 85 High Dynamic Temperature System - Manual (Page 14)

Operator responsibility – Safety recommendations
14
2.5. Cooling water connection
Cooling water pressure (IN / OUT ) max. 6 bar
Difference pressure (IN - OUT ) 3.5 to 6 bar
Cooling water temperature <20 °C
Notice: Cooling water circuit
Risk of oil leaking from the refrigeration system (compressor) of the recirculating
cooler into the cooling water in case of a fault in the cooling water circuit!
Observe the laws and regulations of the water distribution company valid in the
location where the unit is operated.
Notice:
Danger of corrosion of heat exchanger due to unsuitable quality of cooling
water.
 Due to its high content of lime hart water is not suitable for cooling and causes
calcination of the heat exchanger.
 Ferrous water or water containing ferrous particles will cause formation of rust
even in heat exchangers made of stainless steel.
 Chlorous water will cause pitting corrosion in heat exchangers made of stainless
steel.
 Due to its corrosive characteristics distilled and deionized water is unsuitable and
will cause corrosion of the bath. .
 Due to its corrosive characteristics sea water is not suitable.
 Due to its microbiological (bacteria) components which settle in the heat
exchanger untreated and unpurified river water and water from cooling towers is
unsuitable.
 Avoid particulate matter in cooling water.
 Avoid putrid water.
Recommended quality of cooling water:
pH 7.5 to 9.0
Sulfate [SO4 2- ] < 100 ppm
Hydrocarbonate [HCO 3-]/sulfate [SO4 2-]
> 1 ppm
Hardness [Ca 2+, Mg 2+]/[HCO 3-] > 0.5  dH
Alkalinity
60 ppm < [HCO 3-] < 300 ppm
Conductivity < 500 μS/cm
Chloride (Cl -) < 50 ppm
Phosphate (PO4 3-) < 2 ppm
Ammonia (NH3)
< 0.5 ppm
Free chlorine < 0.5 ppm
Trivalent iron ions (Fe 3+) < 0.5 ppm
Manganese ions (Mn 2+) < 0.05 ppm
Carbon dioxide (CO2) < 10 ppm
Hydrogen sulfide (H2S) < 50 ppm
Content of oxygen < 0.1 ppm
Algae growth impermissible
Suspended solids impermissible