Propane versus Butane

[vyv_cox]

Could you elaborate please? Is this a standard hose with a stainless cover or some special metal hose? I would be interested in the latter as I am planning and outside run of hose on my boat.

If its the former I don't understand how it would prevent degradation of the hose by contact with liquid hydrocarbon.

See http://www.gaslow.co.uk/pages/c_s2_1.htm for full information. These are the HP hoses I use.

 

[Ubergeekian]

should be able to cold start ok as coolant at 0 deg will still vapourise the LPG (sometimes needs a timing adjustment if you want to start on LPG) but if vapouriser is freezing this is due to high rate of vapourising and can be solved with a major upgrade of the antifreeze/coolant

At full chat I need about 4hp of heat to vaporise propane. That's 3kW. A gallon (5L) of water has a heat capacity of 5 x 4200 J/K = 21 kJ/K, so that 3kW will drop the temperature at one degree centrigrade every seven seconds.

In practice, of course, there is some heat going into the system, and the thermal mass of the engine stops things cooling as fast. Additionally, though, the vaporiser is plumbed into the head cooling circuit, ie on the engine side of the thermostat. This means that it responds to heat from the engine more quickly, but also means that before that heat starts coming through there is much less water to lose heat.

You can't suck 3kW out of a litre or two of even pure glycol for long!

ps not all LPG autogas forecourt tanks are above ground as some can also be buried i think shell did a few of those

Thanks. I haven't seen any yet, but I'll keep an eye open.

 

[saltylegs]

Don't worry about pressures in cylinders anymore, gas companies stopped using different rated cylinders decades ago, as it is cheaper to design and manufacture one cylinder and just paint it a differnt colour and change the valving. Most butane and propane supplied is BS(certainly in the UK unless you have a brickworks) and this allows for a mix of gases as lpg is a waste gas from the petroleum production. In some countries butane is supplied "dead" and won't vapourise if the temperature comes any where near zero. LPG may be supplied in anywhere from 10-50% mixes in the rest of the world.
Upside down cylinders are not a good idea, (unless you are decanting) as it relies on small diameter pipe to vapourise the gas.
Fork truck cylinders have a dip tube and supply liquid offtake. Vehicle supply tanks also have a dip tube and are liquid offtake.
30mB regs will run propane or butane appliances with no modification.
Propane is a slightly lighter gas than butane, but the bilge dissipation differences in practice are negligible as the explosive limits are also slightly different and you still get an explosive mixture.

in the uk we STILL use cylinders rated for either butane or propane to the standards in the uk you require a shroud around the valve for propane cylinders and the relief valves are also a different setting

and butane boiling point is about -4 deg C and you will have trouble getting it to vapourise (depending on offtake) below +4 deg C
it cannot be supplied "dead" unless you chill it.

 

[saltylegs]

At full chat I need about 4hp of heat to vaporise propane. That's 3kW. A gallon (5L) of water has a heat capacity of 5 x 4200 J/K = 21 kJ/K, so that 3kW will drop the temperature at one degree centrigrade every seven seconds.

In practice, of course, there is some heat going into the system, and the thermal mass of the engine stops things cooling as fast. Additionally, though, the vaporiser is plumbed into the head cooling circuit, ie on the engine side of the thermostat. This means that it responds to heat from the engine more quickly, but also means that before that heat starts coming through there is much less water to lose heat.

.

dont forget that when the engine is running this is waste heat so its not resulting in extra fuel usage

 

[Fire99]

Naa. Both give me Gas. Boom Boom!

 

[Ubergeekian]

dont forget that when the engine is running this is waste heat so its not resulting in extra fuel usage

Of course - and although it's in series with the heater there's no noticeable loss of warmth there. It's still a lot of heat, though, and when the engine is cold there isn't much to spare in the water.

 

[Rum_Pirate]

LPG in the Caribbean - Trinidad to BVI plus the islands in between - is 50% propane and 50% butane. Supplied by SOL.

In the US (Florida) it is 90% propane and 10% butane.




I cannot buy an gas oven from GE because they (GE) have not 'validated' their products for use in the Caribbean??!!?