7
© Baxi Heating UK Ltd 2011
5.0
Ancillary components
5.1
Expansion Vessel
Membrane expansion tanks for solar primary heating circuit.
Manufactured according to the Directive PED 97/23/CE
(approved noZ-DDK-MUC-02-396876-04).
Factory set charge pressure 2.5 bar.
Butyl membrane suitable for solar primary heating fluid, DIN
4807-3 approval.
Maximum working tempe110°C.
Maximum percentage of glycol 40% (Pre-mixed).
Connection: 3/4” BSP male parallel
Expansion vessel supplied with wall mounting bracket and self
sealing vessel connection that will allow removal of the vessel for
maintenance without losing solar heat transfer fluid.
Under the following circumstances, a protection vessel should be
used in the Return Leg of the solar loop from the pump station.
The following distances should be observed:
20 tube collectors should have a Protection Vessel fitted if the
expansion vessel is less than 8 metres away from its nearest
collector. This should be sited at a suitable point between the
expansion vessel and nearest collector.
30 tube collectors should have a Protection Vessel fitted if the
expansion vessel is less than 12 metres away from its nearest
collector. This should be sited at a suitable point between the
expansion vessel and nearest collector.
Instances where a protection vessel should be included
20 tube system
30 tube system
Pipe Diameter
Distance to nearest collector
15mm
<8m
<12m
22mm
<4m
<6m
The size of the protection vessel should be at least the combined
volume of the following:
Total Collector total pipe work volume from collector
to protection vessel.
For positioning on protection vessel (Fig. 7).
5.2
Solar Heat Transfer Fluid
Pre-mixed (40% glycol / 60% water) Solar thermal transfer fluid.
Based on1,2 - propylene glycol with corrosion inhibitors.
DO NOT dilute or mix with water.
Non-toxic, odourless, bio-degradable.
The use of chemical resistant gloves and suitable eye
protection is required when handling.
A full safety data sheet is available on request.
Supplied in 20litre container. Weight of container full - 21kg.
5.3
Thermostatic Blending Valve
Can be set to control the hot water delivered to the user outlets
to a safe working temperature enabling the solar cylinder to store
water at a higher temperature.
Connections: 22mm compression
Max working pressure (static): 14 bar
Max working pressure (dynamic): 5 bar
Min working pressure (dynamic): 0.2 bar
Max inlet pressure ratio: 2:1
Min flow required for stable control: 5 l/min
For pressure drop diagram and dimensions see Figs. 8 & 9
NOTE: For optimum operation the cold connection must be
taken from a balanced cold water feed. For details of balanced
cold water feed please refer to the cylinder manufacturer’s
instructions.
Ø300mm
392mm
3
/
4
”
Expansion vessel
Fig. 6
Flow l/s
Pr
essur
e Loss kPa
0.2
0.3
0.4 0.5
0.7
1.0
1.4
2
30
40
50
70
100
120
140
160
180
200
22mm 28mm
60mm
81mm
92mm
22mm
22mm
Hot
Mix
Cold
Fig. 9
Fig. 8
Fig. 7
