Baxi MULTIFIT Evacuated Tube Collector Kit Instructions page 12

Fig. 12
12 © Baxi Heating UK Ltd 2011
8.0 Installation of pump station
8.2 Pipework installation - general
Connections supplied are suitable for pipe diameters up to
22mm. However for short pipe runs (up to 10m flow and
return) the use of 15mm diameter pipe is acceptable.
The height difference between the highest point in the
pipework (collector) and the pump station may be a maximum
of 15m (this is called the 'static height'). If the static height is
greater than 15m a larger expansion vessel may be required.
Earthing pipework
All solar primary pipework between the solar collectors,
hydraulic station and solar cylinder must be earth bonded to
avoid electrical potential differences. This work must be carried
out by a qualified electrician.
Fit earthing clamps to the solar primary flow and return pipes
and connect the earth clamps to the earthing system of the
property using an earth bonding cable of min. 6mm
Venting the pipework
The Baxi Solarflo hydraulic station includes an air
TM
collector/separator and bleed point so an automatic air vent is
not necessary. Any section of solar pipework that falls and rises
again may require an additional air vent valve to relieve any
trapped air which may cause air locking in the system. The air
vent must be compatible with solar primary systems, i.e. be
resistant to glycol and temperatures up to 200ºC.
Insulating the pipework
External pipework should be insulated with high temperature
resistant materials and be protected against UV degradation.
Internal pipework, especially through unheated spaces such as a
loft space, should also be insulated with high temperature
resistant materials. The Baxi Solarflo
pre insulated flexible stainless steel tubes and with additional
lengths (30m) of stainless steel flexible tubes and high
temperature insulation.
8.3 Solar Expansion Vessel
Solar expansion vessel has a pre-set pressure of 2.5 bar and
must be adjusted to suit your installation.
The charge pressure at the solar expansion vessel should be
adjusted such that when not under load the charge pressure is
0.7 bar above the static system head (the height of the top of
the collector panels above the hydraulic station). A one metre
head represents 0.1 bar. However, the charge pressure should
be at least 1.5 bar.
The maximum static system head is 15m (1.5 bar).
diameter.
2
is supplied with 2x2m
TM