Keston Thermomatic RSM20/FB, Инструкция по установке и обслуживанию, Страница: 7 / 46

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3.3 WATER SYSTEMS
Fig. 3.3 TYPICAL HEATING SYSTEM
3.3.1 Central heating
See Fig.3. f for connections
WARNING: When radiator(s) are at a higher level than the
boiler. A NON-RETURN VALVE MUST BE FITTED lo the
central healing systems flow pipe.
A. Old systems.
These* are likely to contain sludge and debris which, if passed
into the appliance, may cause irreparable damage to the pump
and other components. It is. therefore, highly recommended
that the old system be thoroughly flushed using such as
Fernox cleaner - use in accordance with the manufacturer's
instructions.
B. New systems
Must always be flushed of debris.
C. Design of system
The primary system must be of the sealed type, the designed
temperature rise should be 1 PC.
The following sealed system components are included on the
appliance:
i. Double check valve, stop valve and filling loop,
ii. 8 lilre central heating expansion vessel,
iii. Circulating pump.
iv. CALEFFI relief (safety) valve.
v. D.H.W, Expansion Vessel
vi. Combined temperature and pressure gauge.
D. Expansion vessel/sizing of system
Guidance is provided in BS.7074. Part 1 and BS.5449. The
maximum permissible capacity of the system, including the
appliance, will depend upon the initial design pressure.
As an example, for an initial design pressure of 1 bar the
maximum permitted capacity, including the appliance, is 70
titles.
For calculation purposes:
Existing vessel capacity - 8 litres
(charged at 0.5 bar)
Capacity of appliance - 15 litres
Safely valve setting - 3 Bar
If the system capacity exceeds the allowed value then
an additional vessel must be provided, connected as
close as possible to the appliance heating return.
E. Pressure relief (safety) valve
The valve outlet must be routed to a suitable point of
drainage where there will be no hazard to occupants
and where freezing will not take place.
F. Filling the system
A double check valve, stop valve and filling loop are
supplied. Before using ensure that the arrangement
complies with the requirements of the Local Water
Authority. Alternatively BS 5449:1990 (fig 3.1A) shows
other methods of filling.
Fig. 3.1.A ALTERNATIVE TOP UP SYSTEM
G. System make up
There must be no direct permanent connection to the
mains water supply, hence the filling loop must be
disconnected at one end alter use.
If an automatic top up method is required, then this
must be done via either a cistern which has no other
purpose or a top up bottle. Full details are provided in
BS.5449:! 990 (fig 3.1 B) Again, always check local
Water By-laws before installation. See also Fig.3. l.A.
H. Pump performance
Fig.3.2 shows the pump performance characteristics
and values given take due account of the losses
through the appliance.
I. Thermostatic radiator valves
A by-pass is not required and such valves can be fitted
on all radiators if desired.
J. Drain points
Drain taps should be lilted on the lowest point of the
system, the taps complying with BS.2879
K. Vents
Although an automatic air vent & manual air vent is
provided on the appliance, further facility to vent the
system should be provided.
L. All components and fillings used should be
suitable for temperatures of up to 11O°C and pressures
of up to 3 bar.
All syslem components added must be in occoidance
with US 5-149 and BS.G798.