Much of the following information is from ‘Storage of full and empty LPG cylinders and cartridges’ (1999) published by: LPG Association (now UKLPG), Camden House, Warwick Road, Kenilworth, Warks. CV8 1TH.
LPG includes commercial butane, commercial propane and other mixtures defined under BS: 4250, including Calor gas. Butane is recommended for TCV use. Propane has a higher vapour pressure at room temperature than butane, and hence requires stronger cylinders for storage. Some double burners such as the ‘Dixie 2’ have ‘For Outside Use Only’ on them, which means they are designed for propane. These should be adjusted for butane use by your local LPG dealer.
LPG is normally stored as a liquid under pressure, and any leakage may release large volumes of flammable gases. A very small proportion of these gases in air can create an explosive mixture.
LPG vapour is heavier than air and may flow along the ground or through drains and be ignited at some distance from the source of leakage. In still air vapour disperses slowly. LPG liquid can cause severe frost burns if it comes in contact with the skin.
General information on storage
Note the following:
- LPG should preferably be stored in the open air, but where this is not possible, quantities should be restricted to that shown below in Table 2.1.
- There must be no smoking or use of naked flames at storage points. LPG must be stored away from the workshop area where sparks may be created.
- Refillable LPG cylinders are considered to be ‘full’ whatever the state of their contents, and should be stored and handled likewise. The stated weight of a cylinder refers only to the weight of the liquified gas it can contain, not the weight of the cylinder itself. For example, a 15kg cylinder is one which can contain a maximum of 15kg of liquified gas.
- LPG should be stored away from cylinders containing other gases or hazardous substances.
- Storage should always be at ground level, and never in cellars or basements. Storage areas must always be accessible.
- LPG should not be stored within 2m of a drain.
- The floor of the storage space should be compacted or paved and kept free from weeds, long grass and accumulations of combustible materials.
- Cylinders should not be stored in vehicles.
- Cylinders should always be stored upright, with outlet valves closed, and protective cover, cap or plug in position where supplied.
- Cylinders should never be dropped or knocked violently.
Open air storage
Quantities of between 15 and 400kg stored in the open air must be a minimum of 1m from a boundary, building or fixed ignition source.
Quantities of between 15 and 400kg can be stored against a fence or wall which is not a boundary, or in the angle between two walls. They can also be stored between two wing walls, provided these walls do not exceed 2m in height and length.
Storage in buildings
Quantities stored must not exceed those shown below. Cylinders which are in use, for example in Calor gas heaters, are exempt from the storage requirements.
Table 2.1 shows maximum storage allowance for containerised LPG in shops or offices.
| Building | Max LPG | Remarks |
|---|---|---|
| Residential | 15kg | Unless 60 minutes fire resisting separation is provided between the two occupancies with no direct access between, when up to 70kg may be stored. |
| Non-residential | 70kg | Not more than 5 cylinders or 20 if the maximum capacity is 3kg. No cylinder to exceed 20kg capacity. |
Detection of leaks
Cylinders should be inspected regularly for leakage. Never attempt to find a leak by means of a naked flame. Leakage can be detected by sense of smell, sound of escaping gas, or condensation or frosting around the leak. Soapy water can be brushed over the suspected source, and any bubbles that form confirm the leak.
If a cylinder is found to be leaking and the leak cannot be stopped by closing the valve, inserting the bung or fitting the cap, nearby sources of ignition must be extinguished. Move the cylinder carefully to a well ventilated open space clear of drains. Leave it with the leak (presumably at the valve) uppermost, marked as faulty, with notices prohibiting smoking and other naked lights. Inform the supplier immediately. No attempt should be made by an unqualified person to dismantle or repair faulty cylinder valves.
Fire protection
For storage of less than 400kg, a 9kg dry powder extinguisher should be provided.
Do not try to fight a cylinder fire.
Compliance with the code of guidance
Compliance with the code of guidance should not be a problem for many groups, as few groups will need to store more than five or six 15kg cylinders at a time. However, note should be taken of the limits for storage in buildings with residential accommodation (see Table 2.1 above).
The safest place for storage is to keep the cylinders outside, if necessary in a metal cage or fenced enclosure which can be padlocked for security. A suitable cage could be made out of Weldmesh or similar material. A fenced enclosure or compound should have industrial fences 2m high, with two outward opening gates, not self-locking. Any cage or enclosure must be sited within the limits described above. Contact your local supplier or regional office of Liquefied Petroleum Gas Ltd. for further advice.
