Safety and the UK Law
BS EN 1949:2002 Installation of LPG Systems – Specification for the installation of LPG systems for habitation purposes in leisure accommodation vehicles and in other road vehicles. Key points detailed below:
2. Cylinder Compartment.
2.1 Requirements for the construction of the compartment
With the exception of 2.3 below, cylinder compartments shall be sealed from the inside living accommodation part of the vehicle and shall be accessible from the outside of the vehicle only.
LPG cylinder must be positioned away from heat sources (exhaust system) as described in 2.4 below.
The compartment must be designed so that cylinders can be secured rigidly (to prevent cylinder movement when the vehicle is in motion) and in the upright position with the valve uppermost (to ensure only gas [vapour] can be drawn from the cylinder and not liquid LPG). There must be means of securing cylinders at high, low level.
Access to any connections, changeover valves and pressure regulators must not be obstructed.
Replacement of cylinders must be possible without disturbing any installations or ancillary equipment. Devices to secure cylinders in position must be able to be opened and closed without the use of tools.
No appliances, components or fittings shall be installed in the cylinder compartment that can cause damage the LPG installation or ignite escaping gas. (E.g. batteries or uninsulated electrical components etc.)
2.3 Cylinder compartments accessible from inside the vehicle.
For motor caravans where penetration of a type approved base vehicles bodywork would be required to provide external access, internal access to the cylinder compartment would be permitted providing the following conditions are meet:
Access to the cylinder compartment from the inside living accommodation part of the vehicle is only provided via an attached sealed door or hatch. The bottom of such a door or hatch must be a minimum of 50mm above the floor level of the cylinder compartment. If the cylinder compartment accessible only from inside of the vehicle cannot be ventilated similarly to that referred to in 2.2 above, the following
alternative arrangements must be made:
Ventilation may be provided by a single duct providing the following measures are taken:
Only one cylinder may be installed with a maximum of 7 kg.
The duct shall have a minimum diameter of 20 mm. The maximum length of the duct shall not exceed 5 times the internal diameter of the duct, but may be extended to 10 times the internal duct diameter to avoid interference with under-floor flue outlets.
The duct shall be at low level in the floor and resistant to LPG.
The duct shall fall throughout its entire length to the outside of the vehicle.
Department for Transport - Chapter 10
10.1 Explosions, Fires and Accidents Resulting from Leakage of Liquefied Petroleum Gas (LPG)
10.1.2 The possible dangers associated with the misuse of such installations include fire, explosion and asphyxiation due to the leakage of gas from appliances, storage containers or defective fittings or due to an accumulation of gas following flame failure. Incidents may result in loss of life and sometimes cause serious material damage. The siting of gas consuming appliances and storage containers and the provision of adequate ventilation of the spaces containing them are consequently most important.
10.1.3 In addition to the risk of asphyxiation should the leakage or accumulation of gas occur in an enclosed space, there is also the risk of carbon monoxide poisoning when the appliance is in use. It is dangerous to sleep in spaces where gas-consuming open-flame appliances are left burning and it follows that heaters without flues should not be sited in areas designed as sleeping quarters or in unventilated spaces communicating directly with such areas.
10.1.4 Furthermore, open-flame heaters and gas refrigerators with non-enclosed burners may present a serious hazard from the fire and explosion aspects and if possible, their use should be avoided.
10.1.5 In the United Kingdom the gases most commonly used for domestic LPG installations are butane or propane conforming to BS 4250 -
Commercial butane and propane. A stenching agent is added to enable the presence of gas to be detected by smell even when its concentration in air is below its lower limit of flammability.
10.1.6 It is important to remember with LPG installations that the gases, although heavier than air, if released, may travel some distance tending to fall to the bottom of a compartment. Here they diffuse and may form an explosive mixture with air, as in the case of petrol vapours.