LPG Pump - Pump from red bottle into vehicle/boat fuel tank

[OutInTheShed]

Evanivitch said:

Butane typically burns cleaner, but freeze in lower temperatures. Which is why it's mixed with propane.

Freezing point of Butane is about -140degC.
Butane and propane are mixed together in autogas largely because it comes out of the ground like that.

[Evanivitch]

OutInTheShed said:

Evanivitch said:

Butane typically burns cleaner, but freeze in lower temperatures. Which is why it's mixed with propane.

Freezing point of Butane is about -140degC.
Butane and propane are mixed together in autogas largely because it comes out of the ground like that.

Freeze is wrong term and I oversimplified. You won't get butane vapour for a gas camping stove near zero. Often a shock to people winter camping for the first time. "Summer" camping gas mixes are often pure butane, winter mixes have higher proportion of propane.

Butane is denser, so better energy per volume. Probably not a concern when talking 10s of litres and not 100s of grams.

[SimonYorkshire]

OutInTheShed said:

It's normal to try to transfer the LPG as liquid rather than gas.
With the temperature difference method, the normal problem is avoiding over filling the recipient tank.

The pressure to open the non return valves would be a problem though.
Also does it make a difference that Autogas is a mix of propane and butane, whereas most people refilling cylinders are just talking about Butane?.

Quite a lot of people with campervans and boats have moved towards running their cookers and sometimes heaters from Autogas using refillable cylinders, because Camping Gaz is absurdly expensive per litre and Calor have been shapeless at providing ia reliable supply of smaller cylinders which are cheaper than camping gaz but still several £ per litre.

Is it OK to run an LPG car on pure propane or butane?

Most of your points are not pump related but I'll answer them...

If you overfilled a bottle, simply use an appliance until it's no longer overfilled, or let some gas escape, or transfer some of its gas back into the bottle you filled it from.

Autogas in the UK is 100% propane, on the continent it may be a mix of propane and butane but if so they'll add sufficient butane to prevent lack of pressure in cold weather conditions (they'll change the mixture for time of year). Tank pressure is less important when you're drawing liquid gas than when you're drawing a vapour, if you draw vapour all the gas that you use has to boil (read evaporate) inside the tank, the evaporation has a cooling effect which reduces bottle pressure. When we draw autogas from a tank it's drawn as a liquid, the fuel doesn't evaporate inside the tank so we don't get the cooling effect of that (would be) evaporation and tank pressure remains relatively high. There is still some evaporation because as we draw liquid from the tank the internal volume of liquid decreases while headroom (vapour space) increases, and if the tank is going to stay at the same pressure some liquid boils to form the additional vapour needed to maintain pressure. We can draw gas from a tank/bottle 270 times faster in liquid form while retaining the same tank/bottle pressure compared to drawing vapour. For example we've all seen catering trucks with 'level gauges' stuck to the outside of 47kg propane bottles. The 'level gauge' works on the same principle as the old self adhesive fish tank temperature gauges but instead of having just one 'gauge' that changes colour to show the temperature there's an entire strip of them down the side of the bottle, you can see how full the bottle is when gas is being drawn off in vapour form because there's a change of temperature of the bottle between the headroom (vapour space) in the bottle and the liquid level, the change in temperature is due to the gas being drawn off as a vapour causing cooling evaporation inside the bottle. The same 'level gauge' wouldn't work if we were drawing liquid from the bottle instead of vapour because when we draw liquid we only get a tiny fraction of the cooling effect. The pump will pump the entire contents of a 47kg (92.1 litres) bottle in 30 minutes without the temperature of the bottle changing much. If we were to use that rate of gas take-off from the bottle in vapour form the entire bottle would be very cold and ice would form on its outside.

An LPG converted vehicle will run on propane, butane, or any mix of the two. There is a slight difference in stochiometric ratio (amount of air needed to fully burn an amount of fuel) which would be reflected by slight changes in fuel trim readings on the vehicle but only to the same kind of extent as running a vehicle on 'proper' 100% petrol which we can no longer buy or (say) E5 petrol, not enough difference to be a problem.

Yes some campervans, caravans, boats, etc, use autogas forecourt refillable bottles. They are equivalent to propane bottles because (as said) autogas in the UK is propane. But you can refil them on the continent regardless of any continental mix of propane and butane from forecourt pumps and an appliance will still work. Heh in fact in some areas of the world, e.g. in much of Africa, gas suppliers don't even differentiate between propane and butane. None of this blue/red/green bottle thing that we have in the UK going on, the colour of the bottle there probably only gives a bit of info on which gas company's bottle it is, the customer probably won't be told whether it's propane, butane, or a mix. A regulator designed for propane might have a slightly diffferent pressure output to a regulator designed for butane, for any size flame propane will give more heat but butane will last longer so there's some swings and roundabouts as to which makes most sense for an outdoors application, 100% propane or a mix containing at least some propane necessary in sub zero temperatures. A propane regulator will work with butane and vice/versa but it will usually have the output pressure for which it was designed. At any given temperature a bottle containing propane will have higher pressure than a bottle containing butane but the 'proper' bottles will all withstand the same pressure. It wouldn't be a good idea though to fill one of the small 'disposable' type butane canisters (or say a plastic butane cigarette lighter) with propane, because they probably won't take propane pressure at say 30degC.

It's a bit contradictory to say lots of campervans, caravans, boats, etc, now use forecourt refillable bottles (propane in the UK) then say most people who refill cylinders refill with butane. I'm sure there are plenty people with small campervans, tent campers, etc that refill very small butane canisters / bottles from bigger bottles using the decant method and/or heating method but (given 'self refillable at foreocourts bottles') there are obviously more people who refuel with propane, and obviously by weight or volume far more propane is 'self refilled' than butane.

The pump can pump propane, butane, or any mix. Would need the correct 'end fittings' to connect to the pump setup but they are available from the pump seller. The end fittings are designed to be quick fit 'snap on', it takes only a second to switch from one type of end fitting to another.

Edited by SimonYorkshire on Thursday 21st March 10:09

[OutInTheShed]

SimonYorkshire said:

...
It's a bit contradictory to say lots of campervans, caravans, boats, etc, now use forecourt refillable bottles (propane in the UK) then say most people who refill cylinders refill with butane. I'm sure there are plenty people with small campervans, tent campers, etc that refill very small butane canisters / bottles from bigger bottles using the decant method and/or heating method but (given 'self refillable at foreocourts bottles') there are obviously more people who refuel with propane, and obviously by weight or volume far more propane is 'self refilled' than butane.

There are a significant number of people using autogas in approved refillable bottles.
Personally I know more people who re-fill camping gaz bottles, but it's not something you necessarily want to shout about.
I have known people refill the 'approved refillable' bottles with butane from a big cylinder, because there wasn't an LPG forecourt handy.

[SimonYorkshire]

OutInTheShed said:

There are a significant number of people using autogas in approved refillable bottles.
Personally I know more people who re-fill camping gaz bottles, but it's not something you necessarily want to shout about.
I have known people refill the 'approved refillable' bottles with butane from a big cylinder, because there wasn't an LPG forecourt handy.

I know there are a significant number of people using autogas in approved refillable bottles, and I know that there are a significant number of people using autogas in permanently fitted (to the vehicle) 'vapour take off' LPG tanks (underslung or fitted inside etc)... because I have fitted them. In fact arguably my friend invented the first approved refillable bottle that has the same shape (so will fit in the same place) as a common gas bottle.

Personally I know more people who do the above than fill approved bottles or vapour take off tanks (still approved) but I'm sure some people who don't have a handy forecourt will refil from blue butane bottles like you've said. Refilling from blue butane bottles is no easier than filling from red propane bottles though, so there isn't much reason to favour blue bottles over red bottles.

Perhaps some of those people who you've said refuel from blue (or red) bottles would prefer a pump? Bottled gas is generally cheaper in bigger bottles than in smaller bottles but a big bottle will be more difficult to heat/decant, so the pump could be handy for those people? Definitely a lot less messing about and works consistently and reliably, as opposed to other methods that are more of a faff, more work, less consitent and less reliable.

Edited by SimonYorkshire on Thursday 21st March 12:44

[OutInTheShed]

People who refill the likes of Camping Gaz bottles are mostly trying to save a few quid and get around the difficulties of getting hold of bottles when and where you want one. The adaptor pays for itself in the first refill.
All perfectly legal.

A £300 pump is only going to pay for itself with excise crime on a signifcant scale.

[SimonYorkshire]

OutInTheShed said:

People who refill the likes of Camping Gaz bottles are mostly trying to save a few quid and get around the difficulties of getting hold of bottles when and where you want one. The adaptor pays for itself in the first refill.
All perfectly legal.

A £300 pump is only going to pay for itself with excise crime on a signifcant scale.

Lets define Camping Gaz bottles... You'll mean the relatively very small bottles.

There are people who want to fill much bigger (than Camping Gaz) motorhome leisure gas tanks (e.g. safe fill type or permanently fitted type), the decant method or heating the bottle method isn't going to work for them anywhere near as well as the pump. Road/excise duty is not a factor anymore than it would be for Camping Gaz bottles.

There are people who live some distance from the nearest decent priced forecourt that sells LPG, for them the ability to refuel at home from bottles could make the difference between running on petrol or running on LPG in which case they'd make significant savings if they pay road/excise duty.

There are people who's local forecourt sells gas at a higher price than cost in a bottle plus paying road/excise duty. The pump can save them money if they do pay road/excise duty on gas they buy in bottles.

There are people who have boats on moorings, they cannot easily be taken to an LPG refuelling forecourt. They could use the pump to refuel from a red bottle, or fill a tank on/in a different vehicle at a forecourt then use the pump to transfer LPG from the vehicle tank to the boat.

Motorhome users and campers could use the pump to pump gas from a part full bottle into another part full bottle. Without the ability to do this they sometimes have to decide which bottle(s) to take on a trip. E.g. Gas is running low in the bottle currently in use but it's evening and gas is required all night to run the heater, so the supply is switched to the full bottle to prevent the heater going off at 3am. Which means they may return home with 2 part full bottles. Which means next time they use the camper they have to decide whether to take the 2 part full bottles, or swap one of them for another full one (which one should they swap the fullest or the the one with only a little left in it?). The pump allows them to consolidate the gas from 2 part full bottles into one that's more full (or completely full) and perhaps still take a 2nd full bottle on the next trip.

All the above are legitimate and legal uses, the pump doesn't need to be used for road/excise duty evasion to be worth having in terms of convenience, usefullness, or to save money.

[OutInTheShed]

Anyone with a basic competent grasp of lpg can refill any bottle without a pump, if there are no NRVs to overcome.
Anyone who doesn't understand LPG well enough should probably leave it alone.

Real people I know running LPG heating etc tend to have two bottle systems with auto change-over regulators.

I can imagine the revenue boys getting hold of a pump customer list....

[SimonYorkshire]

If there are no none return valves anyone might be able to transfer gas from one bottle into another using the heat the tank or the decant method. But decant means holding one bottle over the other which is hardly more practical than the pump and heating bottles doesn't seem as safe or practical as the pump either. Heat the bottle method isn't likely to shift much gas from a relatively empty bottle to a relatively full one unless you crank the heat up a few notches but you're not supposed to heat bottles either.

Auto changeover systems are fitted on some campervans but are more common on static caravans and for home heating. In any case auto changeover systems can leave some gas remaining in a bottle in certain conditions.

Can be pessimistic re safety but you've mentioned other methods of transferring gas without mentioning safety concerns of those methods. Can be pessimistic re excise boys but there are plenty legitimate uses for the pump, including filling vehicle tanks from red bottles if duty is paid. If syphons were invented and sold for the first time in motorists shops tomorrow there might be some people telling us how unsafe they were, that we didn't really need one to transfer liquids/fuels from one bottle to another, that excise men and police would surely be calling at the motorists shops and their customers because the syphon might be used for pinching diesel from lorries or transferring fuel that didn't have duty paid on it into vehicle fuel tanks.

[Gavin8rr]

Hi Simon,
I am from Australia and have 2 x EcoLPI (liquid phase injected) vehicles that are fantastic...other than Autogas is gradually disappearing. I need a pump so I can transfer from bottles to vehicles. I have been combing the internet and found your post. Where can I purchase a pump like yours?

Regards,

Gavin