5.6 Connecting the oil/water heat exchanger
For applications with thermally unfavorable ambient conditions, Pfeiffer Vacuum recommends the use of
an optional oil/water heat exchanger. This is fitted at the factory and cannot be retrofitted later on.
The volume of cooling water can be regulated at the control valve in accordance with the operating con-
ditions and cooling water temperature (position 0 => max. flow rate, Position 5 => min. flow rate).
Additional monitoring devices to be provided on site
● A solenoid valve for opening/closing the cooling water supply (stops the supply when the vacuum
pump is switched off).
● A pressure switch for monitoring of the cooling water pressure.
NOTICE
Vacuum pump damage caused by different cooling characteristics
For applications with short switching cycles or increased ambient temperature, there is a risk of dam-
aging the rotor after switching off temporarily.
► Always switch the oil / water cooling off together with the vacuum pump.
► For checking the cooling water flow, use a solenoid valve that only opens when the vacuum
pump is switched on.
Parameter
Cooling water
Appearance
● filtered
● mechanically clear
● visually clear
● no turbidity
● no sediment
● free from grease and oil
pH value
7 to 9
Carbonate hardness, max.
10 °dH
12.53 °e
17.8 °fH
178 ppm CaC0
3
Chloride content, max.
100 mg/l.
Sulfate content, max.
240 mg/l.
Carbonic acid content, max.
not detectable
Ammonia content, max.
not detectable
Electrical conductivity, max.
500 µS/cm
Particle size, max.
150 µm
Cooling water temperature
5 – 35 °C
Cooling water flow
300 l/h
Feed line overpressure, max.
2000 – 6000 hPa
Tbl. 6:
Requirements on the cooling water composition
Required material
● Cooling water hose,
ID 19 mm
● Hose clamps
Installation
28/70
