Introduction
This section deals with the location and protection of a fuel storage container serving a heat producing appliance in a building and the fuel feed system from the container to the appliance where this applies
Oil storage installations
An oil storage tank serving a heat producing appliance in a building and the fuel feed system from the tank to the appliance should be reasonably protected from the effect of fires that may occur in the building being served, or in an adjacent building or premises. This can be achieved by:
(a) isolating the tank by sufficient distance;
(b) protecting the tank by a physical barrier;
(c) enclosing the tank with non-combustible fire resisting construction;
(d) burying the tank.
The tank should comply with OFTEC’s technical specification for tanks. OFS T100 specifies requirements for static thermoplastic tanks and integrally bunded tanks and all rotationally moulded polyethylene tanks should be tested and approved in accordance with I.S. EN 13341. OFS T200 specifies requirements for static steel tanks, with or without bunding.
The risk of water pollution due to oil escape from an oil storage tank serving a heat producing appliance, or from the fuel feed system from the tank to the appliance should be reduced to a reasonable level. This can be achieved by providing:
(a) a storage tank and associated pipework which have adequate resistance to physical damage and corrosion and are designed and installed so as to minimise the risk of oil escaping during the filling or maintenance of the tank;
(b) providing secondary containment when there is a significant risk of pollution (see sub-section 5.2.5); and
(c) providing information on how to respond to a leak, e.g. by fixing an appropriate label to the tank.
Oil storage tank with a capacity not exceeding 3500 litres
An oil storage tank with a capacity not exceeding 3,500 litres should be located in accordance with Table 10. For the purpose of Table 10, the following terms apply:
Bund: a catchpit beneath the tank, without a drain, constructed with non-permeable materials and capable of containing the contents of the tank, plus an additional 10% (see CIRIA Report 163 for the construction of masonry and concrete bunds).
Chamber: a fully enclosed ventilated space, bounded by non-combustible 60 minutes fire resisting construction (see Technical Guidance Document B), including a self closing fire door wholly above the bund level.
Barrier: means a wall or screen having not less than 30 minutes fire resistance (see Technical Guidance Document B) and extending at least 300 mm above and beyond the ends of the tank.
Table HJ10 - Oil storage tanks (capacity not exceeding 3,500 litres) - Extract from TGD J
Secondary containment
Secondary containment, e.g. a nonpermeable bund or integrally bunded prefabricated tank, should be provided where the tank capacity is in excess of 2,500 litres or where there is a significant risk of water pollution should a spillage occur. A significant risk of water pollution is likely to exist where the storage tank is located:
within 10 m of inland freshwaters or coastal waters; or
where spillage could run into an open drain or to a loose fitting manhole cover; or
within 50 m of sources of potable water, such as wells, bore-holes or springs; or
where oil spilled from the installation could reach the waters listed above by running across hard ground; or
where tank vent pipe outlets cannot be seen from the intended filling point.
Protection of an external above ground tank from fire risk
An oil storage tank should be located so as to minimise the possible exposure of the tank from a fire in the building or from an externally sited appliance. Protection of the tank is generally achieved by locating the tank so as to achieve a minimum separation distance from the building/appliance or by the provision of non-combustible fire resisting barriers (see Technical Guidance Document B) or screen walls between the tank and the building/appliance.
An external wall of a building may be considered as a barrier or screen wall where it meets the non-combustibility and fire resistance requirements. In these situations, particular care should be taken in relation to unprotected openings such as doors and windows and the proximity of combustible building elements, such as overhead roof eaves.
Guidance on minimum separation distances from buildings/appliances and boundaries for oil storage tanks is given in Table 11 and BS 5410: Part 1:1997, together with guidance on protection measures, including the
provision of screen walls, where such distances are reduced. Where a tank is used which is not covered by the guidance in BS 5410: Part 1-1997, the protective measures should be appropriate to the level of risk of fire spread to the tank.
The oil feed installation from the oil storage tank to the appliance should conform with the recommendations contained in BS 5410: Part 1-1997, including the fitting of an automatic fuel cut-off valve.
Table HJ11 - Protection of an oil storage tank of not more than 3,500 litres capacity located externally to a building - Extract from TGD J
Oil storage tank with a capacity which exceeds 3500litres
The location of an oil storage tank with a capacity which exceeds 3,500 litres should be in accordance with the requirements of BS 5410: Part 2:2013, as appropriate.
Liquid biofuels
Where liquid biofuel conforming to I.S. EN 14214:2012, or blends of mineral oil and liquid biofuel conforming to OPS 24, is being used the guidance given above for oil installations and in BS 5410-1:1997 is appropriate.
Boilers using bio-liquid blends should be fitted with bio-liquid compatible filters and fire valves, no other modifications are required to the ancillary equipment to facilitate the safe storage and supply of bio-liquid blends. However, it is recommended that all components in contact with oil are proven to be compatible with bio-liquids.
LPG storage installations
This section gives guidance in relation to non complex domestic installations. Further guidance is contained in the following standards:
I.S. 813:2014 Domestic gas installations;
I.S. 820:2010 Non-domestic gas installations (edition 2);
I.S. 3216:2010 Code of Practice-Bulk storage of liquefied petroleum gas (edition 2).
Tank location
LPG vessels up to 2,500 litres capacity (1.1 tonne) sited above ground should be located in the open air in a well ventilated position in accordance with the separation distances given in Table 12.
For separation distances from buildings, in the case of above ground vessels up to 2,500 litres capacity, the separation distances in Table 12 column (D) may be used, provided the construction of the external wall of the building, the area shown shaded in Diagram 21, is non-combustible and is of construction having a minimum period of fire resistance of 60 minutes.
Diagram HJ21 - Small bulk vessel adjacent to a building - Extract from TGD J
The vessel location should be selected to give maximum protection against accidental damage and to take maximum advantage of natural ventilation. The ground beneath or adjacent to connections into vessels or ancillary equipment containing LPG should be concreted, paved or compacted and free from pits, depressions, drains and culverts.
Shrubs or trees provided to screen LPG vessels from view should not interfere with ventilation and therefore should only be located on one side of the installation. Evergreen shrubs or hedges should not be located within a minimum of 1 m from vessels up to 5,000 litres capacity for this purpose. Trees should not be located within a minimum of 3 m from vessels up to 5,000 litres capacity for this purpose.
For underground or mounded vessels reference should be made to I.S. 3216:2010 and should be located so that the manhole and pressure relief valves are in a well ventilated position in accordance with the separation distances given in Table 1 of that document.
Fire walls
Fire walls may be free standing walls built between the tank and the building, boundary and fixed source of ignition or part of the building belonging to the property as per Diagram 21. Where necessary fire walls
should be provided to reduce the effects of radiant heat from fires onto LPG vessels, while ensuring adequate ventilation.
A fire wall should be imperforate and of solid masonry, concrete or similar construction which affords a minimum of 4 hours fire resistance when tested in accordance with the relevant part of BS 476 or a construction giving an equivalent fire resistance and durability.
Except for vessels up to 500 litres (0,25 te) a fire wall should be at least 2 m high or as high as the top of the vessel whichever is the greater and should be sited between 1.5 m and 3 m from the nearest point of the vessel. With the provision of a fire wall, the separation distances may be reduced to the values given in Table 12 Column (D).
For vessels up to 500 litres see Note 1 to Table 12. The distance between the vessel and the specified feature measured around the ends of the fire wall should be equal to or greater than the separation distance given in Table 12 column (C).
In general a wall may be provided on only one side of a vessel. In certain circumstances a wall may be provided on two sides of a vessel provided adequate ventilation is maintained.
Table HJ12 - Fire walls - Extract from TGD J
Cylinders
Location
Cylinders containing commercial propane supplying permanently fixed equipment should be sited and installed outside the building in a well-ventilated area where any leakage of this gas, which is heavier than air, may readily disperse. Cylinders should not be sited where they may be subject to temperatures in excess of 40° C.
Cylinders should be sited away from any heat source likely to raise the temperature of the cylinder contents above 40° C. Cylinders should be sited and installed at or above ground level, never below the ground or in sunken areas or adjacent to open drains or basements or near basement access areas where gas might collect. The part of the structure upon which, or against which the cylinders are located should have a minimum of 2 hour non-combustible fire resistance (see Diagram 22 and Table 13).
Any opening into chimneys or air intakes should be at least 1,0 m above the level of the top of any cylinder. Other openings above any cylinder should be at least 0.3 m above the level of the top of the cylinders (see Diagram 22).
Table HJ13 - Separation distance required between various features or hazards and a cylinder installation (see Diagram 22) - Extract from TGD J
Diagram HJ22 - Siting of LPG cylinder in use - Extract from TGD J
Support
Cylinders should be located on a firm level surface in an upright position with the valve uppermost. Precautions should be taken to prevent cylinders from falling over.
Access
Where there is or likely to be uncontrolled access to the cylinder installation, consideration should be given to protection by a lockable ventilated cage. Appropriate precautions should be taken to protect cylinders against vehicular impact. The installation, its fittings and attachments should be appropriately protected to minimize accidental damage and inadvertent or deliberate interference.
Wood storage
Bulk storage of woody biomass fuel
Woody biomass fuel is highly combustible and precautions are required to reduce the risk of the stored fuel igniting. To ensure maximum energy from the fuel, storage should be designed to be damp free and improve or
maintain the moisture content of the fuel at time of delivery. To inhibit the spread of fire to the contents, bulk storage for wood fuels should be in containers and located in accordance with Table 14.
Table HJ14 - Recommendations for the protection of wood storage - Extract from TGD J
Safety
Fire safety
With automated fuel feed systems, there is a risk of fire burning back from the boiler to the fuel store. To prevent this, there should be an interruption to the fuel-transport system (e.g. a star-feeder or chute for the fuel to fall into the boiler). For large biomass systems, e.g. community systems, a sprinkler-system to flood the fuel transport line in the event of back-burning should also be fitted. Any such sprinkler system should be supplied from an assured mains connection (the relevant safety standards are described in I.S. EN 303-5).
Safety features for pellet or woodchip store
Wood pellet Stores: Pellet-stores should meet special safety requirements to prevent problems such as damage to the store, dust-explosions and moisture-absorption. According to best practice, the ideal pellet-store would display the following features:
solid walls that can withstand the pressure of the pellets, and which are fire resistant for 90 minutes;
completely dry, protected from water or dampness and dustproof;
the filling nozzles through which the wood pellets reach the storage room should be of metal and should not have any right angles, in order to prevent pellet breakages due to the rapid change in direction;
with changes of direction of more than 45 degrees, only curves with a radius of more than 200 mm should be used;
the combined length of the hosepipe and internal piping should not exceed 30 m during filling of the silo ;
the filling and exhaust connector should be earthed with a copper earth wire with a cross section area of at least 4 mm 2 ;
an abrasion and tear -proof impact protection mat suspended opposite the inlet to the store such that the pellets hit the mat absorbing momentum of the pellets and reducing the damage to the pellets from hitting the wall of the store during unloading ;
the mat used should be HDPE-film with a thickness of at least 2 mm or abrasion - proof rubber with a thickness of 1 -3 mm;
fireproof, properly-sealing door to the store with removable wooden boards which allow access when the store is partly full ;
no electrical installations other than those required to operate the system ;
Sloping floor: 35° - 45° ;
wood pellet storage rooms should always have proper ventilation. The use of special ventilation caps on the inblow and exhaust pipes is recommended. These caps allow the exchange of air between inside and outside the storage installation.
Access
Access to hoppers and stores should be restricted for safety reasons. Access doors and lids should be capable of being secured. A safety warning notice relating to the dangers of wood pellet storage should be provided adjacent to the access point.
