Calor/ Propane gas bottles, reallocation of use?

[Archibald Tarquin Blenkinsopp]

Hi, I notice that 15 kg gas bottles are plentiful and inexpensive.

What is the test pressure used in the manufacture and inspection of these?

I was wondering if I could use a couple feeding a homemade spraybar to keep a drive clear of weeds.

I'm fully aware that normal working pressureof butane/ LPG wouldn't be high, but they look like they would stand a few bar and a safe testing procedure would not be difficult to establish.

I thought that If I could test at 12bar and add a relief valve at

10bar, then use the full whack from my compressor of 8 bar to develop the driving force for the weedkiller.

Does this sound feasible and legal?

AB

[Brian Gaff]

One out of 2 possibly! Brian

[Archibald Tarquin Blenkinsopp]

Probably!

But thanks to the data it seems that 20bar is a reachable test pressure. This gives me a very wide margin of safety.

Methinks that there might be laws about modification of the end use of LPG cylinders. If there isn't there should be:-)

I should have a gauge knocking around at the workplace, the only minor problem is a 20 bar + water pump.

As no life form apart from myself and the weeds are going to be present when the contraption goes into service, Ones concience is clear [ish].

AB

[Brian Reay]

In theory, you don't own the bottles (assuming you are in the UK)- at least for those I've dealt with. You have a 'lease', which you pay for, and, at one time, if you returned a bottle with the agreement, you could get part of the fee back. I suppose you really lease a bottle to 'swap' when you get a refill but the concept is the same.

There is something similar in France- we've 'leased' a French bottle (Le Cube) which we use when traveling in France. (You can't get Calor in Europe.) As it was explained, if we return the bottle, we get a partial refund. Otherwise, we swap it (obviously with a few) for a full one when empty.

YouTube is full of people happily cutting open gas bottles to make all kinds of things. Even advice on removing the valves etc.

I'd not do it myself nor would I advise it.

[Archibald Tarquin Blenkinsopp]

No I was warned about cutting the cylinder I took to the local scrapyard. When he wouldn't accept it, I offered to cut it up for him.

I had a wonderfull explanation of how the cylinder walls absorb the gas over the years.

It really did sound impressive and he must have believed it!

I didn't even bother trying to argue.

We had a character working in bottled gasses that had a nice sideline making sleeping policemen out of cylinders. Oxygen, Hydrogen, Propane Co2, anything, it didn't matter and he cut them with a torch :-)

I wasn't official company policy, the P45 was though :-)

AB

[Fredxx]

I simply fill them with water, and then empty them. Hoping anything that will burn will be displaced. I guess it's always possible there might be traces of heavier (liquid) hydrocarbons.

The opened bottle still strongly smells of mercaptans.

[Harry Bloomfield]

It happens that Fredxx formulated :

I have re-purposed them in the past, they make great wood burner, or oil stoves. I just opened the vent and let them breath for a few months, before tackling them.

I found it very difficult to dispose of the smell, plus the dirt residue at the bottom. Rinsing just didn't help much, only opening them up and setting a fire inside worked.

[Rob Morley]

You can get sufficient pressure from a pump intended for air-sprung bicycle shock absorbers, which are available for about a tenner - just fill the bottle (and any plumbing you use to connect it) with water first, so there's minimal energy in the compressed air should anything fail and explode. Obviously use good eye and ear protection.

[Archibald Tarquin Blenkinsopp]

:-)

Funny how One can miss the patently obvious.

Of course, water is still pretty incompressable even if there's an airspace above it.

Thanks, it makes my search for the kit a lot less cash intensive.

I,ll be making a start hopefully next week. At least it will be a use for some of the bits over ordered for the central heating.

Many thanks

AB