Hamworthy Sherborne Series, Installation, Commissioning And Service Manual

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HAMWORTHY HEATING LTD
SHERBORNE 500001103/E
3.0 GENERAL REQUIREMENTS
3.1 Related Documents.
Gas Safety Installations and Use Regulations 1994-
(As amended).
It is law that all gas appliances are
installed by competent persons, in accordance with the
above regulations. Failure to install appliances correctly
could lead to prosecution. It is in your own interest, and
that of safety, to ensure that this law is complied with.
The installation of the boiler
MUST be in accordance
with the relevant requirements of the Gas Safety
Regulations, Building Regulations, IEE Regulations and
the bylaws of the local water undertaking.
The installation should also be in accordance with
any relevant requirements of the local gas region
and local authority and the relevant
recommendations of the following documents :-
British Standards
BS 5440: Part 1:
Specification for installation of flues.
Part 2: Specification for installation of ventilation for gas
appliances.
BS 6644: Installation of Gas Fired Hot Water Boilers -
60 kW to 2MW.
BS 6700: Design, installation, testing and maintenance
of services supplying water for domestic use.
BS 6880:Part 1, 2 & 3: Code of practice for low
temperature hot water heating systems of output
greater than 45 kW.
BS 7074:Part 1: Application, selection and installation
of expansion vessels and ancillary equipment for sealed
water systems.
Part 2: Code of practice for low and
medium temperature hot water systems.
CP 342: Centralised hot water supply. Part 2: Buildings
other than individual dwellings.
I. Gas E. Publications
IGE/UP/1
Soundness testing and purging of
industrial and commercial gas installations.
IGE/UP/1A Soundness testing and direct purging of
small low pressure industrial and commercial natural
gas installations.
IGE/UP/2 Gas installation pipework, boosters and
compressors in industrial and commercial premises.
IGE/UP/10 Installation of gas appliances in industrial
and commercial premises Pt 1 flued appliances.
Health and Safety Executive: -
Guidance note PM5 - Automatically controlled steam
and hot water boilers.
CIBSE Publications:- "CIBSE Guide"
It is impractical in this document to specify all relevant
information, but the following extracts from the above
references are emphasised since failure to comply with
these requirements will almost certainly result in an
unsatisfactory installation.
Third edition of the 1956 Clean Air Act
Memorandum.
Department of the Environment, Scottish
Development Department & Welsh Office.
3.2 Feed Water Quality
If the boiler feed water has a high degree of
hardness, it is recommended that the water be
treated to prevent precipitation of scale or sludge in
the boiler water passageways. Details of additives
can be obtained from any reliable manufacturer of
water treatment products or the local water
authority.
It should be noted however, that even if the boiler water
is of average hardness, not requiring treatment,
subsequent draining of the system for repair or constant
make-up water due to an undetected leak will cause
additional deposits and gradual build-up of scale. It is
essential therefore, that leaks are attended to promptly
and draining is kept to an absolute minimum.
It is recommended that the system be flushed out at
least twice before any water treatment is added. If any
doubt exists regarding the internal cleanliness of an old
system, consideration should be given to the fitting of a
coarse filter in the return pipework to the boilers.
3.3 Adequate Water Flow
The Hamworthy Sherborne boiler is designed as a
quick response, low water content unit, to run
continuously with maximum reliability. Care should be
taken in the initial design and layout having due regard
for adequate water flow through the boilers and the
influence of the system controls.
The Sherborne range of
boilers operate with flow/return
temperatures of 50/35°C (condensing) or 80/65°C (high
efficiency) to ensure that the correct output as given in
Figure 2.2. is achieved.
If the temperature/flowrates of the application
cannot meet those given in Figure 2.2. it may be
necessary to incorporate mixing valves and shunt
pumps to ensure that the boiler will operate
satisfactorily.
Figure 2.2. shows recommended and minimum
water flows required with the associated pressure
losses. The control system and valves, where fitted,
should be regulated to avoid lower flows occurring.
The flow corresponding to 15°C temperature rise
across the boiler is the minimum recommended
at any time.
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