How much C02 in lifejacket canister?

[MLGR]

Volume of CO2 in a cylinder

If my memory of chemistry is correct, then 1 gm.Molecular weight of a gas gives 22.4 Litres.
CO2 has a molecular weight of 44 (Carbon 12, O2, 32) Thus a cylinder containing say ,44g CO2 will produce 22.4 L gas.

 

[rosssavage]

Ok, mobo owner so not too genned up on AVS etc.. but surely at 90 deg the mast gets wet? And as 90 is less than 116, wouldn't this (assuming the bouancy is enough) arrest the roll rate and encourage self righting????

I accidentally set off one of my lifejackets whilst servicing it last month - no over px valve..., and a wasted co2 bottle!!

 

[Boo2]

I hope never to find out whether my boat is stable
inverted! I do however think that 15kg of buoyancy at a 6meter distance will give you a considerable turning moment..

15kg at 6m is 90 kg.m of turning force or about the same as 90kg (litres) of water at 1 m (roughly the topsides height or half deck width) for a small yacht.

So it will have no beneficial effect to speak of, being far too small to prevent an inversion if waves have forced the mast to the horizontal position.

Boo2

 

[knuterikt]

well lashed on to minimise flapping and windage

And how would you apply a lashing that does not prevent it from inflating?

 

[sam_uk]

15kg at 6m is 90 kg.m of turning force or about the same as 90kg (litres) of water at 1 m (roughly the topsides height or half deck width) for a small yacht.

So it will have no beneficial effect to speak of, being far too small to prevent an inversion if waves have forced the mast to the horizontal position.

Boo2

I accept it won't prevent a inversion, it will encourage her to come back round again.

The positioning of a 14 stone man on my small 20ft yacht will make her lean one way or the other a bit, so that is quite illustrative, thanks.

I would fold the jacket 'back to back' so that it was a long thin thing, then tie the bit that would usually rest on your neck at the top, and the bit that would rest on your waist at the bottom.

 

[KREW2]

This is correct, all liferafts will have dump valve because the differences in temp may affect the volume of gas being put in from the bottle and you want your liferaft to fully inflate even in (especially in) sub zero temperatures.

The same cannot be said for lifejackets- the volume of gas put in is so small temp variations make little difference and it is possible to top up orally after inflation.

150N= 33gm cylinders, 175/190N=38gm cylinders and 275N=60gm cylinders.

I think the reasoning behind the liferaft having a dump valve is that you don't really want to try and inflate it to full pressure by mouth, or pump, so there needs to be plenty of Co2 in the canister.
The reassurance is once fully inflated it will stay that way for at least 48 hours, hence there is more gas than needed, necessitating dump valves to stop it bursting.

 

[nimbusgb]

Any chance you could run that one by me again.......?

On the spec sheet the AVS is 116 degrees. The boat has a beam of 3.9m and a fairly short rig. The mast is far from getting wet at 90 degrees. the base is still probably a metre, perhaps a little more from the water surface. The boat doesn't float around the deck/mast joint. On reflection the top of the mast would probably be just under at 116.

She's an Oceanis 390, one of which stayed firmly upside down in the Bay of Biscay.

 

[rosssavage]

On the spec sheet the AVS is 116 degrees. The boat has a beam of 3.9m and a fairly short rig. The mast is far from getting wet at 90 degrees. the base is still probably a metre, perhaps a little more from the water surface. The boat doesn't float around the deck/mast joint. On reflection the top of the mast would probably be just under at 116.

She's an Oceanis 390, one of which stayed firmly upside down in the Bay of Biscay.

Ah, ok. Hadn't considered the beam of the boat.... Mobo's eh... aren't we thick?

 

[Baggywrinkle]

Have you considered something from here ...

http://www.sailboats.co.uk/category~4875.html

I was considering one for my cat for a while, then I discovered from experience that it didn't invert when I capsized it as the mast was full of polystyrene.