Baxi Solo 2 60 RS Installation And Servicing Instructions page 10

Pressure
Safety
Gauge
Valve
Expansion
Vessel
Boiler
System Drains
at Low Point
Method of determining minimum
value of expansion vessel volume for
sealed systems using Baxi Boilers
Vessel Charge Initial System
Pressure (Bar) Pressure (Bar)
0.5
1.0
0.5
1.5
2.0
1.0
1.0 1.5
2.0
1.5
1.5
2.0
System Volume = 75 litres
Example :-
Vessel Charge Pressure = 1.0 bar
Initial System Pressure = 1.5 bar
Then :- 75 x 0.152 = 11.4 litres
Expansion Vessel Volume
NOTE
Where a vessel of the calculated size is not
then the next available larger size should
10
3 Litre
Air
Top Up Bottle
Vent
(If Required)
Filling
Point
Pump
Radiator
Circuit
Max Boiler Flow
O
Temp = 82 C
Multiply Total
Water Content Of
System By (Litres
0.067
0.112
0.207
0.441
0.087
0.152
0.330
0.125
0.265
Sealed Systems
SAFETY VALVE
A safety valve complying with the requirements of BS
6750 Part 1 must be fitted close to the boiler on the
flow pipe by means of a horizontal or vertically upward
connection with no intervening valve or restrictions and
should be positioned to facilitate testing. The valve
should be pre-set and non-adjustable to operate at a
pressure of 3 bar (45 Ibf/in
discharge any water or steam through a pipe to a safe
outlet position.
PRESSURE GAUGE
A pressure gauge of minimum range 0-4 bar (0-
60 Ibf/in 2 ) with a fill pressure indicator must be
fitted to the system, preferably at the same point
as the expansion vessel in an easily visible
position.
EXPANSION VESSEL
An expansion vessel complying with the
requirements of BS 4814 must be fitted to the
system by means of a connection close to the inlet
side of the circulating pump in accordance with the
manufacturers instructions, the connecting pipe
being unrestricted and not less than 15mm (
nominal size. The volume of the vessel should be
suitable for the system water content and the nitrogen
or air charge pressure should not be less than the
system static head.
Further details of sealed system design can be
obtained from BS 5449: Part 1 and the British Gas
publication entitled 'Specifications for Domestic Wet
Central Heating Systems'.
FILLING POINT
A filling point and an approved stop valve to BS 1010
must be fitted at low level and the method used for
filling the system should be approved by the local
water undertaking. For further details see BS 6798.
MAKE UP SYSTEM
A method of replacing water lost from the system
should be provided either by means of a make up
vessel of not more than 3 litres (5 pints) capacity,
mounted above the highest point of the system, or by
pre-pressurisation of the system.
VENTING
A method of venting the system during filling and
commissioning must be provided by fitting automatic
air vents or by venting manually.
HOT WATER STORAGE
The hot water storage vessel must be of the indirect
coil type. All components used in the system must be
suitable for operation at 110
pressure allowed by the safety valve.
2 ). It must be arranged to
1 / in)
2
O C (230 O F) and at the