Carrier AQUASNAP 30RB series Installation, Operation And Maintenance Instructions page 16

30RB/30RQ - 30RBY/30RQY
Carrier recommendations on heat exchange fluids:
• No NH ammonium ions in the water, they are very detrimental for
4+
copper. This is one of the most important factors for the operating life
of copper piping. A content of several tenths of mg/l will badly corrode
the copper over time (the plate heat exchangers used for these units
have brazed copper joints).
• Cl- Chloride ions are detrimental for copper with a risk of perforations
by corrosion by puncture. If possible keep below 10 mg/l.
• SO sulphate ions can cause perforating corrosion, if their content is
42-
above 30 mg/l.
• No fluoride ions (<0.1 mg/l).
• No Fe and Fe ions with non negligible levels of dissolved oxygen
2+ 3+
must be present. Dissolved iron < 5 mg/l with dissolved oxygen < 5
mg/l.
• Dissolved silicon: silicon is an acid element of water and can also lead
to corrosion risks. Content < 1mg/l. Water hardness: > 0.5 mmol/l.
Values between 1 and 2.5 can be recommended. This will facilitate
scale deposit that can limit corrosion of copper. Values that are too
high can cause piping blockage over time. A total alkalimetric titre
(TAC) below 100 is desirable.
• Dissolved oxygen: Any sudden change in water oxygenation
conditions must be avoided. It is as detrimental to deoxygenate the
water by mixing it with inert gas as it is to over-oxygenate it by mixing
it with pure oxygen. The disturbance of the oxygenation conditions
encourages destabilisation of copper hydroxides and enlargement of
particles.
• Electric conductivity 600µS/cm
• pH: Ideal case pH neutral at 20-25°C - 7 < pH < 8
Do not introduce any significant static or dynamic pressure into the heat
exchange circuit (with regard to the design operating pressures).
GB - 14