Glow-worm Ultimate 100FF - Manual (Page 11)

11 221966B
3.11 Expansion Vessel
A diaphragm type expansion vessel, conforming to the current
issue of BS4814 (see also BS7074 Part 1 and 2) must be
connected at a point close to the inlet side of the circulating
pump, see diagram 3.4, unless laid down differently by the
manufacturer.
The expansion vessel volume depends upon the total water
system volume and the initial system design pressure. For any
system an accurate calculation of vessel size is given in the
current issue of BS5449 and BS7074 Part 1, for IE refer to the
current edition of I.S.813 "Domestic Gas Installations".
Example. For an initial system design pressure of 0.7bar the
minimum total vessel volume required is 0.063xTotal System
volume.
NOTE: A higher initial design pressure requires a larger volume
expansion vessel.
The charge pressure must not be less than the static head of the
system, that is, the height of the highest point of the system
above the expansion vessel.
The water content of the boiler is given in Data Table 1.
3.12 Pressure Gauge
A pressure gauge with a set pointer and covering at least the
range of 0 to 4bar (0 to 60lb/in
2 ) shall be permanently fitted to
the system in a position where it can be seen when filling the
system.
Diagram 3.2
6349
FEED AND
EXPANSION
CISTERN
22mm VENT
(MIN.)
15mm (MINIMUM)
COLD FEED
OPEN VENTED FULLY PUMPED WATER SYSTEM
RECOMMENDED RELATIONSHIP BETWEEN
PUMP COLD FEED AND VENT
450mm
MIN.
HEIGHT
1150mm
MIN.
RETURN FLOW
CYLINDER
PUMP
HEATING
150mm
MAX.
There must
always be a
cold water
path to the
return
connection
of the boiler.
BOILER
28mm (MINIMUM)
BY-PASS WITH
LOCKSHIELD VALVE
FLOW
RET.
Diagram 3.3
28mm
PIPE
FLOW
RETURN
4273
1metre Min.
27 metres
Max.
22mm FOR COMBINED FEED & VENT
TO BE FITTED IN ACCORDANCE
WITH BS 5449
INDIRECT
CYLINDER
ALTERNATIVE
SYSTEM
CONTROL
VALVES
HEATING
SYSTEM
PUMP
FULLY PUMPED CIRCULATION
BYPASS (DIAGRAMMATIC)
BYPASS 28mm
MIN WITH
LOCKSHIELD
VALVE
1metre Min.
27 metres
Max.
INDIRECT
CYLINDER
ALTERNATIVE
SYSTEM
CONTROL
VALVES
HEATING
SYSTEM
PUMP
FULLY PUMPED CIRCULATION
BYPASS (DIAGRAMMATIC)
BYPASS 28mm
MIN WITH
LOCKSHIELD
VALVE
22mm VENT & 15mm COLD FEED
TO BE FITTED IN ACCORDANCE
WITH BS 5449
6459
6466
3 Water Systems