10
4 - HYDRAULIC CONNECTIONS
4.1 PRELIMINARY INFORMATION
4.3 OPERATION SEQUENCE
Before connecting the unit, carefully wash the system by filling
it and emptying it several times with clean water.
Ignoring this operation will lead to several filter cleaning inter-
ventions and at worst cases can cause damages to the e-
xchangers and the other parts.
Execute leakage test before isolate the pipes.
To avoid heat dispersions and formation of condensate isolate
all the pipes. Leave various point of service free (wells, vent-
holes etc ).
4.5 RISK OF FREEZE
4.6 ANTI-FREEZE SOLUTION
Consider that the use of anti-freeze solution determines an
increase in a pressure drop.
Make sure that the glycol type utilized is inhibited (not corrosi-
ve) and compatible with the hydraulic circuit components
(pump etc).
Do not use different glicol mixture (i.e. ethylic with propylene)
Selection and installation of system components must be
carry out by installer.
Following you will find some indications to integrate with what
is provided by the local regulations in force and by the good
technical laws.
4.2 COMPONENTS
CUT-OFF VALVES :
installed at inlet and outlet (both on the water technique
circuit as well as that of the hot domestic water) allow
maintenance operations without having to empty the
system .
THERMOMETERS AND MANOMETERS :
installed at entry and exit of the main elements facilitate
inspection and maintenance.
AN AIR BLEED VALVE :
installed in all of the highest points of the system allowing
the venting of the circuits air..
DRAINAGE TAPS :
installed in the lowest points of the system to allow
bleeding.
EXPANSION TANK :
It keeps a correct system pressure when the water
temperature changes. It must be dimensioned as a
function of water content. Could be necessary install in
addition on the unit one or more of it .
WATER FILTER :
must be installed immediately in the water input of the unit,
in a position that is easily accessible for cleaning.
The filter never should be removed, this operation
invalidates the guaranty
SUPPORTS :
The hydraulic pipes weight mustn’t burden on the unit
connections
If the unit or the relative water connections can be subject to
temperatures close to 0°C adopt measures for prevent risk of
freeze.
For example:
Mix water with ethylene glycol
Safeguard the pipes with heating cables placed under the
insulation
Empty the system in cases of long non-use and check that:
there are no closed taps present that could trap water
even after emptying
there are no low points in which water can stagnate
even after emptying; carry out any blowing required .
4.4 WATER QUALITY
The water quality is determined by the following factors, avoid
therefore:
Inorganic salts
pH
Biological load (seaweeds etc)
Suspended solids
Dissolved oxygen
Water with inadequate characteristics can cause:
pressure drop increase
energy efficiency decrease
corrosive symptom increase
