3. General Requirements
3.1 Related Documents
Installation of air heaters must be in accordance with the relevant
requirements of:
BS 5410: Part 2: 1978 Code of Practice for Oil Firing
Installations of 45kW and Above
The Building Regulations
The I.E.E. Regulations
It should also be in accordance with relevant requirements of
the local authority and fire authority, in addition the following
British Standard Codes of Practice must be observed
CP.3 Ch IV Precautions Against Fire Part 2 Shops and
Departmental Stores Part 3 Office Buildings,
and the relevant publications of OFTEC.
3.2 Location
The location chosen for the air heater must permit the provision
of a satisfactory flue system and an adequate air supply. The
location must also facilitate ease of servicing and satisfactory
air circulation around the heater.
The air heater must be installed strictly in accordance with any
fire regulations or insurance company's requirements
appertaining to the area in which the heater is located, particularly
where special risks are involved such as areas where petrol
vehicles are housed, cellulose spraying areas, and wood working
departments etc.
The air heater must be installed either:
(a) suspended by chains or straps of adequate strength to
safely carry the weight of the unit and ancillary equipment
or
(b) On specifically designed cantilever brackets from a non-
combustible wall or
(c) On a level non-combustible surface which is capable
of adequately supporting the weight of the air heater and
any ancillary equipment.
The heater must not be installed in conditions for which it is
not specifically designed e.g. highly corrosive atmospheres,
vitiated atmospheres, or where adverse wind conditions may
be experienced. Where the location of the heater is such that it
might suffer external mechanical damage e.g. from overhead
cranes, fork lift trucks etc. it must be suitably protected.
Any ducting should be kept as short and direct as possible having
regard to the distribution of the heated air.
Any combustible material adjacent to the heater and flue systems
must be so placed as to ensure that its temperature does not
exceed 65°C (150°F).
3.3 Oil Supply
3.3.1 Main Storage Tank and fittings
Construction and installation should be in accordance with:
(a) BS 5410 Part 2 Section 6
(b) BS 799 Part 5
(c) BS 1563 and BS1564
The latter three standards apply to cast iron sectional, mild steel
sectional, and mild steel welded tanks respectively and therefore
must be applied appropriately.
3.3.2 Service Tanks and fittings
3.3.2.1 Construction
These should be designed and constructed in accordance with
BS 799 Part 5
3.3.2.2 Installation
The installation should be in accordance with:- BS 5410 Part 2.
In addition the service tank installation must comply with local
regulations and by-laws and with the requirements of insurance
companies
3.3.3 One Pipe System (Storage to burner)
3.3.3.1 General
Refer also to the detail provided in the burner handbook
regarding
pipe sizing. These must be generally in accordance with B S
799 Part 3 and BS 5410 Part 2.
Particular attention is drawn to the following:
a) Pipe jointing compounds must be capable of withstanding
the solvent action of the fuel oil under all operating
temperatures and pressures. Jointing compounds containing
oil shall not be used. Hemp and other fibrous materials shall
not be used as packing for screwed joints.
b) Soft solder copper tube fittings and galvanised pipes and
fittings must not be used.
e) Oil lines must be completely air-tight.
d) The pump suction must not exceed a maximum of 0.4 bar
(30cm Hg). Beyond this limit gas may be released from the
oil.
3.3.3.2 Single Pipe System - Gravity Feed
Warning:
The burners are supplied adjusted for a single pipe
system. If the burner is to be used on a twin pipe system the
Internal bypass plug of the burner oil pump must be fitted. Refer
to the burner instruction booklet.
Ideally the return pipe should terminate within the oil tank at
the same level as the suction line, both being below the minimum
oil level.
3.3.4 Fire Valve
It is recommended that the fire valves should be installed as
follows:
1. Main storage to service tank supply (if applicable)
2. Main storage to burner supply
3. Service tank to burner supply (if applicable)
Fire valves should be installed generally in accordance with the
requirements of BS 799: Part 5. The fire valve should be situated
in an easily accessible position as near the tank as possible and
where practicable within the boundary of the tank chamber or
catchpit retaining wall.
3.4 Flue System
The flue system should generally be in accordance with
BS 5410 Part 2.
Materials used for the flue system should be mechanically robust,
resistant to internal and external corrosion, noncombustible and
durable under the conditions to which they are likely to be
subjected. Prevention of condensation within the flue should
be an important factor in the design of the flue system. In order
to minimise condensation the use of doublewalled flue pipe or
insulation is recommended.
Where condensation in the flue is unavoidable, or rain ingress
is possible, provision must be made for a condensate drain
connected to a suitable drain or gully. The condensation pipe
from the flue to the disposal point should be of non-corrodible
material of not less than 22mm (¾ in) size.
Facilities should be provided for disconnecting the flue pipe
from the air heater for inspection and servicing purposes. Bends
with removable covers should be fitted for inspection and
cleaning purposes where considered appropriate.
The flue should terminate in a freely exposed position and must
be situated such that products of combustion do not enter any
opening in a building in such concentration as to constitute a
health hazard.
3.5 Air Supply
Where the air heater is to be installed in the space to be heated
it requires the space containing it to have a permanent air vent
direct to outside air. The air vent should have negligible
resistance and must not be sited in any position where it is likely
to be easily blocked or flooded, neither should it be positioned
adjacent to an extraction system carrying flammable vapour.
The air supply requirement that follows is related to the
maximum rated heat input of the heater, or heaters if more than
one is installed in the same space.
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