CIAT 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 silica: silica 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).
Outlet available static pressure of the unit with hydraulic module
Data applicable for pure water at 20°C
Data applicable for:
- Fresh water 20 °C
- In case of use of the glycol, the maximum water flow is reduced.
300
290
280
270
260
250
240
230
220
210
200
190
180
170
160
150
140
130
120
110
100
90
80
70
60
50
0.0
EREBA ACCESS 17 - 40 T/HT
0.5
Legend
EREBA ACCESS 17 T/HT
1.
EREBA ACCESS 21 T/HT
2.
EREBA ACCESS 26 T
3.
EREBA ACCESS 33 T / 26 HT
4.
EREBA ACCESS 33 HT
5.
EREBA ACCESS 40 T/HT
6.
An hydraulic connector is available inside the unit for sizes 17-21 kW. A
picture of this part is shown here below. The aims of this part is to have
the same dimensions between water outlet and water inlet.
3
2
1
1.0
1.5
Water flow rate, l/s
EN - 10
6
5
4
2.0
2.5