Gas bottles

[GrahamE]

Hi all, just the first of many 'a quick one'.

When my caravan is in storage btween trips and over winter should i bring the gas bottles home or do most people leave then in the van ?.

 

[ProfJohnL]

Hello Graham,
The deceision may have already been made for you. If you are using a storgage site then there may already be a requirement for you to remove the bottles (even empty ones) from the caravan. some sites have dedicated gas bottle storage areas for this purpose.
The reasoning is that if there were a fire in a caravan, the presence of gas botles could pose a danger of explosion or at least fueling a fire further.
If the site does not have a bottle storage area, then you are faced with the problem of transporting the bottles away from the site.
Most caravanners I know tend to bring the caravan to their house before and after a trip so it can be loaded or unloaded. this is an opertunity to remove the gas bottles and store them at home. This avoids having to put the bottles in the car which is strictly not recommended.
Caravan gas bottles must always be stored & secured to prevent them from falling over even when being transported or used.

 

[otherclive]

Keep them at home. It stops someone nicking them from your van when in store.

 

[RayS]

Have a care, I'm sure there are 'rules' about how many you can keep at home )in the garage ?) and if you have too many say 2 from the van and 1 from the BBQ and 1 for luck you may be over the top both legally and for insurance reasons. 'Empty' bottles can be leathal as they are not actually empty - the remaining LPG plus some air over time will actually make a more explosive mix than 100% gas.

Prof J will doubtless explain if asked, but pure hydrocarbon will not burn/explode in the absence of oxygen. In the chemical industry we used to purge centrifuges and other machinery handling flammables with nitrogen to reduce the risk. Took gas samples looking for oxygen and fervently hoping not to find any.

 

[ProfJohnL]

Hello Ray,

Give me an inch and I'll take the whole hundred miles!

Ray S is correct. For a hydrocarbon fuel to burn it requires access to oxygen. LPG cylinders contain no oxygen (or at least they shouldn't) so the liquid and vaporised gas inside which is either Butane or Propane cannot burn or explode through chemical action.

As for haw many or much LPG you can leagaly have at a dwelling see the following document:
http://www.epa.govt.nz/hazardous-substances/using-storing/common-substances/lpg/Pages/Limits-for-using-and-storing-LPG-indoors.aspx

As for where to store LPG cylinders see:
http://www.hse.gov.uk/pubns/chis5.pdf

It is very rare indeed for an LPG bottle to explode due to the internal combustion of its content. It is actually quite difficult to get enough air inside a cylinder to produce an explosive mixture, and even harder to introduce a source of ignition. Look how complicated car engines are which are essentially trying to do just that!

The more common (but still infrequent) cause for the "explosion" of an LPG cylinder is when its surrounded by a fire, where it's the heat from the external fire that raises the temperature and pressure of the LPG inside the cylinder. Ultimately the hydraulic pressure of the LPG may split the cylinder and allow the content to escape. Under such conditions the escaping gas will be ejected at very high pressure and can throw a jet of gas and liquid a very long distance. This will rapidly spread the fire.

What is more common is for the brass valve to give and vent the pressure. That can create a very spectacular but dangerous fire show. If a cylinder is not secured upright, it may be knocked over and the force of the ejecting vapour or liquid can turn the cylinder into a very destructive missile. I have seen a factory wall destroyed by just such a missile.

Imagine what a 4.5kg butane cylinder yet alone a 45Kg Propane cylinder hurtling towards you can do.
Imagine what a 20M or more high fountain of burning LPG could do to the roof of your garage and the bedroom above.

And that's not all, even with out a flame, Liquefied gas can burn or more precisely cause frost bite. LPG is stored under pressure to keep it in its liquid form. The liquid needs heat to vapourise in to its gas state, and to do it grabs heat from anything it touches. Pure liquefied Propane will cause a sever deep burn on the skin. Butane will also, if exposed to enough of the liquid.

This may read as all doom and gloom, but provided LPG is used correctly and safely then it is still one of the cleanest and most convenient high energy fuels available.

 

[otherclive]

Keep them at home. It stops someone nicking them from your van when in store.

When I say at home it doesnt mean indoors. Mine are stored in the garden behind the compost heap, but be assured that the heat from the heap presents no risk to the bottles.
Prof your link from New Zealand doesnt connect.

 

[hortimech]

Hi prof, your link to the New Zealand webpage appears to have '%C2%A0' on the end of it, not that it matters really, as I am sure that New Zealand laws are not enforceable here in the UK

Try http://www.calor.co.uk/customer-services/lpg-safety/lpg-cylinder-storage/cylinder-storage-information/ instead.

 

[ProfJohnL]

Thank you Hortimeh,

I must have cut and pasted the worng link. You are perefctly correct, the NZ regs are not enforceable in the UK. Thanks for posting the Calor link. actually the general advice is very similar where every you are, its ceratin details that may be different.
If anyone is doubt about their own arrangmants for storing personal gas cylinders, then consult your loacl planning office.

 

[otherclive]

I think the Calor link gives good advice and I'd suggest the local Fire and Rescue Service Fire Safety Officer is better than the Local Planning Office as the former will visit your house if required. But frankly its best to leave them outdoors when not in the van, especially propane. I wouldn't even store butane indoors even if I had a gas heater in the house.

 

[GrahamE]

My Storeage site rules do allow you leave them disconected in the van but i will bring them home, Did have my Hazchem licence up till about 8 yrs ago so i understand most of what has been said. Thank you for all the replys.