JULABO FW95-SL Ultra-Low Refrigerated Circulators - Manual (Page 14)

Operator responsibility – Safety recommendations
14
2.5. Cooling water connection
Cooling water pressure (IN/OUT) max. 6 bar
Pressure difference (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, hard water is not suitable for cooling and causes
scale in the heat exchanger.
• Ferrous water or water containing ferrous particles will cause formation of rust
even in heat exchangers made of stainless steel.
• Chlorinated water will cause pitting corrosion in heat exchangers made of
stainless steel.
• Due to their corrosive characteristics, distilled water and deionized water are
unsuitable and will cause corrosion of the bath.
• Due to its corrosive characteristics, sea water is not suitable.
• Due to its microbiological (bacterial) 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