Worcester Greenstar Heatslave 12/18 Technical Information page 18

Fig. 1 Tank installation near combustible buildings & boundaries.
Clearances required when additional protection is not provided.
Combustible boundary (note 1)
300mm
Minimum
760mm
300
clearance
mm
Non combustible
base (note 2)
Oil tank
300mm
Minimum
1.8m
Combustible wall
300
clearance
of building (note 3)
mm
NOTES: Relevant to Fig. 1 Where the tank is next to a non
combustible wall (minimum 30
1. Combustible Boundary (has less than
minutes fire resistance)
30 minutes fire resistance)
Where the tank is located over an
2. Non Combustible Base. Covers area
existing non combustible surface
beneath tank and extends 300mm
outside the tank on all sides except: 3. Combustible Wall of Building
(has fire resistance of less than
30 minutes to internal fire)
Fig. 2 Tank installation near combustible buildings & boundaries
Protection required where clearances in Fig. 1 are not provided.
Combustible Boundary (note 1)
300mm
Less Than
760mm
Clearance
Available
Fire Protection Non Combustible
Barrier (note 4) Base (note 2)
Oil Tank
Less Than
Combustible Wall 1.8m Clearance
300
of Building (note 3) mm Available
NOTES: Relevant to Fig. 2 Where the tank is located over an
existing non combustible surface
1. Combustible Boundary (has less than
30 minutes fire resistance) 3. Combustible Wall of Building (has
fire resistance of less than 30
2. Non Combustible Base. Covers area
minutes to internal fire)
beneath tank and extends 300mm
outside the tank on all sides except: 4. Fire Protection Barrier (Non
combustible, minimum fire resistance
Where the tank is next to a non
of 30 minutes, extends 300mm
combustible wall (minimum 30
beyond both ends of tank and
minutes fire resistance)
300mm higher than the tank)
Fig. 3 Tank installation near non combustible buildings
& boundaries
Building wall without openings. No added protection required.
Non combustible boundary (note 5)
Can be less than
300mm
760mm clearance
300
mm
Non combustible
Oil tank
base (note 2)
Min. 1.8m Min. 1.8m
Non combustible wall of building (note 6)
NOTES: Relevant to Fig. 3 5. Non combustible boundary (has
minimum fire resistance of 30
2. Non Combustible Base. Covers area
minutes). Must extend 300mm higher
beneath tank and extends 300mm
than the tank and 300mm beyond
outside the tank on all sides except:
both ends of the tank.
Where the tank is next to a non
6. Non Combustible Wall of Building
combustible wall (minimum 30
(has minimum fir resistance of 30
minutes fire resistance)
minutes). Any part of the wall within
Where the tank is located over an
1.8m of the tank must have a fire
existing non combustible surface
resistance to internal fire of not less
than 30 minutes and have no
openings other than airbricks.
For more information refer to BS 5410 :
Part 1 : 1997, OFTEC Book Three and Technical sheet T1/131.
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Fig. 4 Tank installation near non combustible buildings
& boundaries
Building wall with openings. Opening protection required.
Non combustible boundary (note 5)
Can be less than
300mm
760mm clearance
300
mm
Non combustible Oil tank
base (note 2)
Min. 1.8m
Opening at least 1.8m Non combustible wall of Opening less than 1.8m
from tank. building with opening fire protection barrier
No protection required (note 7) required
NOTES: Relevant to Fig. 4 5. Non combustible boundary (has
minimum fire resistance of 30
2. Non Combustible Base. Covers area
minutes). Must extend 300mm higher
beneath tank and extends 300mm
than the tank and 300mm beyond
outside the tank on all sides except:
both ends of the tank.
Where the tank is next to a non
7. If wall has openings closer than 1.8m
combustible wall (minimum 30
to tank then a fire protection barrier
minutes fire resistance)
300mm higher than the tank and
Where the tank is located over an
300mm beyond the tank can be
existing non combustible surface
fitted. The non combustible building
4. Fire Protection Barrier (Non
wall and the barrier must protect
combustible, minimum fire resistance
the tank from fire coming through
of 30 minutes, extends to non
the opening.
combustible wall, 300mm beyond
both ends of tank and 300mm higher
than the tank)
Fig. 5 Tank installations under eaves
Without protection of eaves
Eaves
Minimum 1.8m
Piers or raised Oil tank
base if required
Non combustible
base (note 2)
NOTES: Relevant to Fig. 5 Where the tank is next to a non
combustible wall (minimum 30
2. Non Combustible Base. Covers area
minutes fire resistance)
beneath tank and extends 300mm
outside the tank on all sides except: Where the tank is located over an
existing non combustible surface
Fig. 6 Tank installations under eaves
With protection of eaves
300
300
mm
mm
Eaves
Less than
Fire protection
1.8m
cladding (note 8)
Piers or raised Oil tank
base if required
Non combustible
base (note 2)
NOTES: Relevant to Fig. 6 8. Fire protection to combustible eaves
(must provide a minimum resistance
2. Non Combustible Base. Covers area
to fire of 30 minutes, extends the
beneath tank and extends 300mm
length of the eaves over the tank with
outside the tank on all sides except:
an additional 300mm at both ends).
Where the tank is next to a non
The cladding of the eaves is to
combustible wall (minimum 30
prevent fire spreading to the roof
minutes fire resistance)
from the area of the tank.
Where the tank is located over an
existing non combustible surface
Oil supply
The oil burner on the Greenstar Heatslave is supplied with a
single flexible fuel line from the oil pump which the installer
connects the main oil supply line to (via the oil isolation
valve), within the appliance. This enables the burner to be
removed without the need for disconnection of the fuel line.
The maximum permissible head is 4 metres. If the head is
greater, then a head breaking device must be incorporated
into the oil supply line.
The oil pump's primary job is to pressurise the oil once in
the pump and force it out of the nozzle at high pressure to
atomise the fuel to ensure clean and efficient combustion.
This same pump can also be converted to 'draw' up the fuel
line in cases where the oil tank is lower than the
appliance's burner. This conversion is undertaken by the
installing engineer.
All oil pumps on Worcester appliances can easily be
converted to work on a two pipe system (details of this
operation are within the Installation and Servicing
instructions which come with the appliance).
More advice on fuel lines can be sought from OFTEC Book
Three and Technical sheet TI/134.
De-aeration devices
A de-aeration device is a container of oil about the size of a
pint glass with an automatic air vent on top and three
connections on the bottom. It saves running a return oil
pipe back to the tank from the burner as in Fig.11. Its
function is to provide a reservoir of oil from which the oil
pump draws oil whilst venting any air in the oil to the
atmosphere preventing nuisance 'lockout' of the burner. Not
all the oil drawn is consumed and any excess is returned to
the de-aeration device, so whilst the burner is firing there is
a continuous flow and return of oil. The third connection is
for the main fuel line from the oil tank. There is usually a
non-return valve located in this connection to prevent oil
draining back towards the oil tank under gravity and
creating a vacuum. When the burner is firing the whole fuel
supply system is under negative pressure i.e. suction,
therefore it is imperative that all joints on the fuel supply
system are sound. Whilst there may be no obvious signs of
an oil leak externally, when the burner is firing it may be
possible for air to be drawn in through a bad joint, reducing
the pump's capabilities, resulting in a lack of fuel to the oil
pump and nuisance 'lockout'. This may manifest itself as a
very low level of oil or 'foaming' of the oil inside the de-
aeration device whilst the burner is trying to fire.
Most de-aeration devices are made of plastic and vent to
the atmosphere. For this reason they must always be
located externally, if sited internally they would constitute a
fire hazard (see Fig. 12).
Metal types do exist which do not emit vapour. These can
be located internally or externally. Plastic pipe specifically
for oil lines does exist and is acceptable but must be used
underground.
Top outlet oil tanks should have the non return valve
removed from the end of the oil feed pipe within the tank if
installed in conjunction with a de-aeration device.
Supply pipe
The oil supply pipe itself would normally be annealed
copper tube with a protective plastic coating which is easily
manipulated around bends and usually enables the fuel line
to be run in a continuous length without joints. If joints
must be used, they must be accessible, even if underground
(via an access duct) and should be of the manipulative
type. Plastic pipe specifically for oil lines does exist and is
acceptable but must only be used underground.
Galvanised pipe, fittings and soldered joints must not be
used in oil lines.
More advice on fuel lines can be sought from OFTEC Book
Three and Technical sheet TI/134.
Supply pipe sizing
The diameter of the oil supply pipe itself is subject to the
distance from the oil tank to the appliance and the head of
oil whether it be positive or negative.
Tables 1 and 2 give the required diameter of supply pipe
when cross referenced with the head. Table 3 gives the
diameter of the supply pipe when the use of a de-aeration
device is made.
Table 1 Single pipe gravity feed system
Maximum allowable pipe run (metres)
Head 8mm inside dia. pipe 10mm inside dia. pipe
(m) (10mm OD copper) (12mm OD copper)
0.5 12 30
1.0 25 69
1.5 37 91
2.0 49 100
2.5 62 100
3.0 74 100
3.4 87 100
4.0 99 100
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