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SYSTEm DESIgN
COLD AND HOT WATER DISTRIBUTION DESIgN - ALL mODELS
Torrent models are designed to be fed directly from mains. They fulfill the
requirements of Water Byelaw 91, and therefore
do not require a check valve
to be
fitted to the supply pipe. The performance of the Torrent is directly related to the
adequacy of the cold supply to the dwelling. This must be capable of providing for
those services which could be required simultaneously and the maximum demand
should be calculated. Torrent will operate at dynamic pressures as low as 1.5 bar (at
the appliance) which must be available when local demand is at its maximum, but
the preferred range is between and 3.5 bar.
As a general guideline, although a 15mm external service may be sufficient for the
smaller dwelling with one bathroom, a mm service is preferred (5mm MDPE)
and should be the minimum for larger dwellings.
If a water meter is fitted in the service pipe, it should have a nominal rating to match
the anticipated maximum simultaneous hot and cold water demand, calculated in
accordance with BS 6700. This could be 50 litres per minute in some properties.
If the incoming static mains water pressure exceeds 3.5 bar at any point in the 4
hour cycle then a pressure limiting valve set at 3.5 bar should be fitted downstream
of the stop tap where the cold supply enters the property. Units must be fitted
strictly in accordance with the requirements of the Local Water Undertaking who
should be consulted prior to installation. In the event of any difficulty please contact
us as the manufacturer. Equipment used in the system should be suitable for a
working pressure of 10 bar.
A typical arrangement for the hot and cold water system is shown in Figure 3.
BALLVALVE/OVERFLOW - ALL mODELS
Because it supplies the whole of the primary/heating system a ballvalve and overflow
must be installed in the feed and expansion cistern when the Torrent Indirect is used
in an open vented heating system. A ballvalve and overflow can also be fitted with
Torrent Direct models or Torrent Indirect models fitted in sealed primary heating
systems.
However because it only supplies the thermal store the feed and expansion cistern
on these two appliances/systems can be filled manually if required ie through a hose
pipe fitted with a double check valve. In this situation an overflow can still be fitted
if required to ensure that if a leak occurs on the internal coils it can be discharged
safely to the outside of the building and not discharge internally from the feed and
TYPICAL HOT AND COLD DISTRIBUTION
Check valve NOT REQUIRED unless
supply pipe services more than one dwelling
Check valve NOT REQUIRED unless
scale inhibitor is a chemical type.
Pressure limiting valve
(Not required unless mains pressure is greater than 3.5 bar)
Supply
pipe
Second dwelling
Sink
Scale inhibitor
(where necessary)
Bath
H.B.
W.C.
BS11
Ballvalve
Figure 3 Hot and Cold Distribution Pipe Arrangement - All models
Note: The cold feed to the
Torrent should approach
from below to avoid heat
creepage during idle
periods.
expansion cistern itself.
If a ballvalve is fitted
a warning/overflow pipe must always be
fitted.
USE IN HARD WATER AREAS
- ALL mODELS
The patented design of the heat exchange
module is such that the turbulence through
the coil slows down the formation of scale in
even the hardest water conditions, at normal
operating pressures. However, where the water
can be considered hard, it is recommended that
an effective proprietary in-line scale inhibitor is
installed. It is important that where the supply
to the Torrent is in mm the in-line descaler is
also mm. In practice servicing is not normally
required but in hard water areas requirements
can be considered similar to those needed for
instantaneous or ‘combi’ appliances.
The installation of the scale inhibitor should
be in accordance with the manufacturers
instructions and with the Water Byelaws.
PLASTIC PIPEWORK - ALL mODELS
This appliance is suitable for use with
plastic pipework as long as the material
is recommended for the purpose by the
manufacturer and is installed fully in accordance
with their recommendations. We recommend
the use of barrier pipe for heating systems,
which will mean the system can have British
Gas service cover in regions offering this service.
A short 300mm length of copper pipe must be
fitted at the hot outlet from the thermostatic
mixing valve.
WATER TREATmENT
In all Torrent models treating the primary
water will not contaminate domestic hot
water supply.
Summary of Contents for Torrent T144 DE
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