Glow-worm economy plus c 50 Instructions For Use, Installation & Servicing page 9

3 LITRES (0.66 gals)
MAKE-UP BOTTLE
(if required)
NON-RETURN
VALVE
(Make-up
alternatives)
SEALED WATER SYSTEM DIAGRAMMATIC LAYOUT
3.6 Expansion Vessel
A diaphragm type expansion vessel, conforming to the current
issue of BS4814 (see also the current issue of BS7074 Part 1
and 2) must be connected at a point close to the inlet side of the
circulating pump, see diagram 3.3, unless laid down differently
by the manufacturer.
The expansion vessel volume depends on the total water
system volume and the initial system design pressure. For any
system an accurate calculation of vessel volume size is given
in the current issue of BS7074 Part 1.
Example: For an initial system design pressure of 0.7bar the
minimum total vessel volume required is 0.063xTotal System
volume.
Guidance is also given in the current issue of BS5449.
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 capacity of the boiler is given in Section 1.
3.7 Pressure Gauge
A pressure gauge with a set pointer and covering at least the
range of 0 to 4 bar (0 to 60lb/in
the system in a position where it can be seen when filling the
system.
3 Water Systems
AUTO
AIR
VENT
FLOW
RETURN
DRAIN
COCK
2
) shall be permanently fitted to
15mm (min)
BY-PASS WITH
LOCKSHIELD
VALVE
SAFETY
VALVE
BOILER
EXPANSION VESSEL SYSTEM
EXPANSION VESSEL
PRESSURE (BAR)
INTIAL SYSTEM
PRESSURE (BAR)
EXPANSION VESSEL
VOLUME (LITRES)
EXPANSION VESSEL
PRESSURE (BAR)
INTIAL SYSTEM
PRESSURE (BAR)
EXPANSION VESSEL
VOLUME (LITRES)
A = SYSTEM VOLUME
9
AIR
RELEASE
POINT
FILLING POINT
CIRCULATING
PUMP
PRESSURE
GAUGE
EXPANSION
VESSEL
Diagram 3.3
0.5
0.5 1.0
A X 0.075 A X 0.126
1.0
1.0 1.5
A X 0.098 A X 0.171
Diagram 3.4
221462C