HAMWORTHY HEATING LTD
5
SHAFTESBURY HE
500001049/N
5.6.1 Oil Storage Tank
- The oil storage tank
should be of sufficient capacity to permit economic
deliveries of oil to be taken. Reference should be
made to oil distributor for advice. The tank should
be installed such that:
a.
The oil outlet should be higher than the top of the
oil burner pump. If site conditions prevent this, then
a suction lift (or 'two-pipe') fuel supply system must
be used.
b.
The maximum head on the suction side of the oil
pump should not exceed 4 metres (14 feet).
c.
The base should be sloped away from the outlet
and towards a drain cock to allow draining of any
water or sediment from the tank.
d.
It is sited outside, if possible, and complies fully
with the requirements of the relevant British
Standards and Local Authority Regulations.
5.6.2 Oil Supply Lines
- The oil supply line(s)
between storage tank and burner should be run in
copper, steel or aluminium pipe. Galvanised pipes
and fittings should not be used. All pipework and
fittings must be oil-tight, with any screwed joints
made good with an oil resistant compound. The
supply line should terminate adjacent to the burner
with an isolating valve and metal bowl filter (with
replaceable filter element). All burners are supplied
with flexible oil pipes to make the final connection
between the oil supply pipe and the burner.
5.6.3 Gravity Feed Supply
- Where the delivery
connection of the storage tank is above the level of
the pump inlet on the burner a 'single pipe' gravity
feed system can be used. At no point in this system
should the supply pipework be higher than the
lowest level of fuel in the tank.
5.6.4 Suction Lift Supply
- where the delivery
connection of the tank is below the level of the pump
inlet on the burner a 'two-pipe' fuel supply system
MUST be used. This system uses the burner pump
to provide a circulation of oil to and from the tank.
N.B.
Burner pumps can be supplied ready for use
on a 'single-pipe' system. For use on a 'two-pipe'
system it may be necessary to fit the pump with a
by-pass plug. Refer to technical information
supplied with burner.
The return line should terminate within the oil tank at
the same level as the suction line, in which case a
non-return valve is not required. If the return line
terminates above the fuel level, a non-return valve
MUST
be fitted.
6.0 FLUE SYSTEM
6.1 General Requirements
Detailed recommendations for flue systems are given in
BS 6644
,
IGE/UP/10,
"Flues for Commercial and
Industrial Gas-Fired Boilers and Air Heaters."
The following notes are intended to give general
guidance only.
The flue passages within the Shaftesbury HE
operate under pressurised conditions and in order to
eliminate any additional resistance, it is
recommended that the flue system shall be adapted
to its design diameter as soon as possible, after
leaving the boiler.
The boiler should be connected to a single flue
system in the case of a single boiler, or a common
flue header in the case of a multiple boiler
installation. Flue systems must be self supporting,
contain access for cleaning and contain a
maintenance joint near the boiler outlet to allow for
removal of the flue box during servicing.
Shaftesbury HE boilers are suitable for installation in
a balanced compartment in accordance with the
requirements of
BS 6644.
Consult Hamworthy
Heating Technical Department for help or
assistance if in doubt.
6.2
Design Waste Gas Volume and Temperature
It is recommended that the volume and temperature
of the waste gases used for design of the flue
system are as shown in Figure 16.4
6.3 Materials
Materials used for the flue system must be mechanically
robust, resistant to internal and external corrosion, non-
combustible and durable under the conditions to which
they are likely to be subjected.
Consideration should be given to possible freezing of
condense water traps and pipework. This must be
avoided at all times. Insulate condense pipes if freezing
temperatures are likely to be encountered.
Chimneys should be lined with a non-porous acid-
resistant material in accordance with BS.5854, e.g.
a flexible flue liner or similar British Gas Approved
material. The internal diameter of the liner must not
be less than the recommended flue size and the
number of joints should be kept to a minimum.
Any joint between the flexible liner and the flue pipe
from the boiler should be made using a purpose
made connector. Existing chimneys should be
thoroughly swept before use and any register plates,
dampers, or restrictions removed.
If the boiler(s) is not connected to a chimney
system, but is connected directly to outside by a
standard stainless steel flue (either single or twin
wall) it is particularly important to ensure that the
point at which it exits the building is fully
weatherproofed.
6.4 Suction
The flue system should be designed to maintain
atmospheric pressure or a slight suction at the boiler
flue connection at all times (0.1 - 0.3mbar).
It is recommended that a draught stabiliser is fitted to
the flue system where the suction is likely to exceed
0.3mbar.
