Section 7: Sealed Systems
! NOTE !
Ensure that the expansion vessel used is of sufficient size
for the system volume.
Refer to BS 7074-1 or The Domestic Heating Design Guide
for sizing the required vessel.
7.1.2 PRESSURE GAUGE
The pressure gauge must have an operating range of 0 to 4 bar.
It must be located in an accessible place next to the filling loop for
the system.
7.1.3 PRESSURE RELIEF (SAFETY) VALVE
The pressure relief (safety) valve should be fitted in the flow
pipework near to the boiler.
The pipework between the pressure relief (safety) valve and boiler
must be unrestricted, i.e. no valves. The pressure relief (safety)
valve should be connected to a discharge pipe which will allow
the discharge to be seen, but cannot cause injury to persons or
damage to property.
7.1
SEALED SYSTEM REQUIREMENTS
All Grant VortexBlue models are suitable for use with sealed
systems complying with the requirements of BS EN 12828, BS EN
12831 and BS EN 14336.
The system must be provided with the following items:
•
Diaphragm expansion vessel complying with BS EN 13831
•
Pressure gauge
•
Pressure relief (safety) valve
•
Approved method for filling the system
7.1.1 EXPANSION VESSEL
The expansion vessel should be fitted in the return pipework
as shown in Figures 7-1 and 7-2. To reduce the operating
temperature of the expansion vessel, position it below the pipe to
which it is connected.
The expansion vessel may be positioned away from the system,
providing the connecting pipe is not less than 13 mm in diameter.
If the expansion vessel is connected via a flexible hose, care must
be taken to ensure that the hose is not twisted or kinked.
Figure 7-1:
Sealed system
Figure 7-2:
Sealed system boilers
If thermostatic radiator valves are
fitted, the system
must
incorporate an
adequate by-pass.
7 SEALED SYSTEMS
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