Pressure
Gauge
Filling
Point
Pump
0
V I
Expansion
Vessel
Radiator
Circuit
Safety
Valve
Al
Vent
3 Litre
Top Up Bottle
(If Required)
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 lbf/In9. It must be arranged to
discharge any water or steam through a pipe to a
safe outlet position.
,
--
IUSERMIESEMBEEMES
A pressure gauge of minimum range 0-4 bar
(0-60 lbf/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.
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
(
V
2
in) 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'.
I*4111.101W4.13/4.
-
System Drains
at Low Points
Max Boiler Flow
Temp = 82°C
Pr
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Vessel Charge
Pressure (Bar)
1
Initial System
Pressure (Bar)
Multiply Total
Water Content
Of System by
(Litres)
0.5 -'
'0.5
1.0
1.5
2.0
0.067
0.112
0.207
0.441
1.0
1.5
2.0
0.087
0.152
0.330
1.5
2.0
0.125
0.265
Vetherohardtplessure
nitialljjlein-preicute
5
Ekpans
yatem_volume
0' 5
raire
/
rot
-t
e n
,
41,6
'Op Oa
Pe
NOTE
w
of the calce‘
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e27
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-1
0‘
e
-9
e,
ta
ble
se
siz
e
e
then the neXt
-nould be used.
- 0 10,i-
A filling point and an approved stop valve to BS 1010
must be fitted at low level and the method used for
fillingthe system should be approved by the local
Water undertaking. For further details see BS 6798.
afAXEMEISYSIEMEMENZEMES
A method of replacin9 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.
A method of venting the system during filling and
commissioning must be provided by fitting automatic
air vents or by venting manually.
-Worn
,
Am; .
0
tom
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°C (230°F) and at the
pressure allowed by the safety valve.