11
Solar Expansion Vessels
CoolSky offer a range of different sizes of
Zilmet Solar Expansion vessels. These should
be sized according to match the
requirements of the system to which they
are connected.
(note : solar expansion vessels should be installed with
the hydraulic connection to the top as this will reduce
heat transfer into the vessel, as shown above)
The Solar Expansion Vessels include 12, 18
and 24 litre versions which have been
specially designed for solar. Other sizes are
available upon request.
The Membrane
Inside the expansion vessel there is a special
Zilan E solar membrane structured as a bag
membrane that separates the gas from the
solar liquid. The development of the
membrane is a result from long term Zilmet
field experience in the installation of vessels
in thermal solar systems.
The membrane is stable with the Pre-Mixed
Propylene-Glycol within the solar loop up to
50% mixtures and has a max. working
temperature of 110° C. The vessel can
accommodate short peaks of 130°C glycol
temperature.
The Zilan E solar membrane is also less likely
to trap air and consequently, there is a lower
likelihood of corrosion damage to the steel
vessel.
Expansion Vessels are manufactured in
accordance with the PED 97/23/CE and
EN13831 directives, which mean that they
are fit for use in closed solar energy heating
systems according to DIN 4757 and
EN12977.
Expansion Vessel Technical
Specification
Max. Operating Pressure:
6bar
Membrane Temperature:
10° - +100°C
System Temperature:
-10° - +100°C
Factory pre-charge:
2.5 bar ±20%
Nominal volume:
12, 18 & 24 L
Colour:
White
Cool Tip
The Cold-Fill Pressure of the Solar
System should be :
1.3 + (0.1 x Static Height)
Where the Static Height is in
Meters.
Expansion Vessel Pressure should
be re-set to 0.3 Bar less than the
Cold Fill Pressure.
