Gulfstream GS A-Class 12/OV, Design, Installation & Servicing Instructions, Page: 16 / 44

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Page 16
Table 3.2 Expansion vessel requirements
Safety valve settings (bar) 3.0
Initial vessel charge pressure (bar) 1.0 1.5
Initial system pressure (bar) 1.0 1.5 1.5 2.0
Total water content of system (1) Total water content of heating system (1) Expansion vessel volume (litres)
120 20 13.1 19.2 18.7 39.7
135 35 13.7 21.6 21.1 44.7
150 50 16.4 24.0 23.4 49.7
175 75 19.1 28.0 27.3 57.9
For other volumes multiply the system content by factor 0.109 0.190 0.156 0.331
Total system water content (1) = 100 + heating system water content (1)
Table 3.3: Discharge pipe sizes
Height-h
(m)
Pipe size
(mm)
Maximum
length-Le
(m)
0.2
15 1
22 9
28 30
0.3
15 2
22 13
28 45
0.4
15 3
22 19
28 63
0.6
15 4
22 27
28 94
0.8
15 5
22 27
28 127
1.0
15 7
22 46
28 157
3.3.3 Open vented heating system
(a) Open vented (‘-OV’) models are only suitable for an open vented heating system shown
schematically in figure 3.5.
(b) F & E cistern: The cistern supplied with the unit, can be fitted up to 10m above the base
of the appliance i.e. the maximum static pressure in the appliance must not exceed 1.0
bar. The water level in the F & E cistern should be at least 250mm above the highest point
on the system including the radiators.
(c) Overflow pipe: The overflow/warning pipe should be in 20mm internal diameter pipe of
suitable material for use in heating systems in accordance with BS 5449 (such as copper).
It should have continuous fall and discharge in a conspicuous external position. It should
not have any other pipework directly branched into it.
Cold feed and open vent: This appliance uses combined cold feed and open vent. This
should be run in 22mm copper pipe and connected to the Feed and Expansion cistern
as shown in figure 3.5.
Figure 3.5 Schematic diagram of the open vented heating system
SYSTEM DESIGN
GulfStream A-CLASS
OV models
Figure 3.2 Schematic Diagram of the Sealed Heating System
350mm minimum clearance
Mains Cold Water
Overflow/Warning Pipe
h > 250mm
22mm Combined Cold Feed
And Open Vent
M
aximum
H
eigh
t
Per
mitt
ed
=
10
met
ers