Connecting an external gas supply.

Currently set up on site in Spain, we have our safari room set up and don't really want to take it down to go fill the underslung lpg  tank. Would it be possible to connect a gas bottle up via a regulator  to our external gas point to supply bottled gas to the system. I would first of all isolate the underslung tank. Most of the campers are using gas as the cost of electricity is quite high.

Lots of people do exactly that. As long as you use an appropriate bottle top regulator so it's low pressure gas entering the system, it should work fine.

(Caveat! Only my opinion - I'm not a qualified gas engineer.)

The Truma instruction say:

"Only suitable for removing gas, not for feeding gas into the system"

Whether that's just a safety net for them if you blow yourself up or whether there is a technical reason, I don't know.

No help to you now, Gaslow supply a connector from an unregulated cylinder to the LPG fill point on the van. The bottle 'gasses off' into the tank and supplies the system through the van's regulator.

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looks pretty simple...

I don't have a gaslow system but I do have an on board tank, I'll check to see if that hose will fit to my fill point.

Believe the onboard tank is the same as the gas low system. Take care though as this will be unregulated high pressure gas when going into the filling point.

You should have a none return valve on the cylinder prior to attempting to fill from a cylinder. Not something I would do, you are in effect decanting which is frowned upon

roli wrote:You should have a none return valve on the cylinder prior to attempting to fill from a cylinder. Not something I would do, you are in effect decanting which is frowned upon

Agreed Roger.

I'm sure Messrs Gaslow know what they are doing, but their high pressure connector makes me feel a bit uneasy.

Thinking logically, feeding low pressure gas into the system at a point other than the usual one seems perfectly OK to me. If you consider the system as a length of pipework with a stopper at the end, it makes no difference where the regulated, low pressure gas is fed in.

I emphasise "low pressure" as that seems the crucial point. A suitable bottle top regulator must be used if gas is to be fed in from a bottle via the BBQ point.

However, my earlier caveat remains in force. Loads of people do it, but I'm not a qualified gas engineer.

roli wrote:You should have a none return valve on the cylinder prior to attempting to fill from a cylinder. Not something I would do, you are in effect decanting which is frowned upon

If I understand the Gas flow site , this system does not decant any liquid at all. It purely sends gas through your empty on board tank to feed your regulator , with no intention of putting liquid into the on board tank. Never seen it before, but looks a great idea to me. I have in the past run a BBQ through two regulators but it does drop the final  pressure at the burner.

With Gromit's caveat; we have been using the external BBQ socket for tens of years and no probs but am careful and watch hose life etc. Advantage with BBQ point is you can keep gas in onboard tank for travels etc. Running through the gas flow adaptor the tank I believe would have to be empty or you would need a bottle of higher pressure and then not sure how well it would work.  I believe autogas is a butane-propane mix so you could only use propane. Can you get propane in Spain?

I think ill contact gaslow for some clarification on what i can and cannot do. The original idea of using the bbq point was so i could isolate the onboard tank for use when travelling but have the ability to use regulated bottled gas when on site for extended periods.

Some people have suggested having a tee in point downstream from the tank isolation valve, but is that not what the bbq point is.

An interesting thread, on my Corinium, it’s a gasit system....it looks as though the filling point has an internal thread, however when I tried to fit a high pressure hose, it would not screw in...either left hand or right!

Ray

Libraryman2 wrote:An interesting thread, on my Corinium, it’s a gasit system....it looks as though the filling point has an internal thread, however when I tried to fit a high pressure hose, it would not screw in...either left hand or right!

Ray

The internal thread in the gasit filling point is for screwing in adaptors for use in European countries.

Justus2 wrote:

Libraryman2 wrote:An interesting thread, on my Corinium, it’s a gasit system....it looks as though the filling point has an internal thread, however when I tried to fit a high pressure hose, it would not screw in...either left hand or right!

Ray

The internal thread in the gasit filling point is for screwing in adaptors for use in European countries.

Hi yes, with ref to an earlier post, the hose required is the reserve hose (GI-0080) £16.50 plus postage
I emailed gasit and it is the correct proceadure, I’m waiting for an answer to the question of the regulator, my logic tells me that it just uses the regulator of the mh...therefore no additional regulator required just the bottle and connection point.

Ray

Libraryman2 wrote:

Justus2 wrote:

Libraryman2 wrote:An interesting thread, on my Corinium, it’s a gasit system....it looks as though the filling point has an internal thread, however when I tried to fit a high pressure hose, it would not screw in...either left hand or right!

Ray

The internal thread in the gasit filling point is for screwing in adaptors for use in European countries.

Hi yes, with ref to an earlier post, the hose required is the reserve hose (GI-0080) £16.50 plus postage
I emailed gasit and it is the correct proceadure, I’m waiting for an answer to the question of the regulator, my logic tells me that it just uses the regulator of the mh...therefore no additional regulator required just the bottle and connection point.

Ray

Further to this last mail; gasit tell me that they don’t have an adapter to fit the Spanish bottles!
I read this as the only way to use the system in Spain is to take a bottle and the correct adapter with you!!!

Other points are that the underslung tank does NOT have to be empty and another regulator is not nessasary...

Ray

ray, i have a Gaslow 'jumbo' adaptor which i keep for back up should i need to connect a spanish bottle, i have a large locker (and a changeover valve) and i would just put the  2nd bottle nect to my Gaslow.
these adaptors are readily available at local ferreterias (hardware shop) and should fit the 21.8mm LH thread on the end of the reserve hose
WHOOPS.....fun with inserting my first image.....sorry.....trying to delete some of these ...better, i think...[You must be registered and logged in to see this link.]

Jaytee wrote:With Gromit's caveat; we have been using the external BBQ socket for tens of years and no probs but am careful and watch hose life etc. Advantage with BBQ point is you can keep gas in onboard tank for travels etc. Running through the gas flow adaptor the tank I believe would have to be empty or you would need a bottle of higher pressure and then not sure how well it would work.  I believe autogas is a butane-propane mix so you could only use propane. Can you get propane in Spain?

Caveat still in force! 

I think you are almost exactly right, and that this (highlighted) is what the OP is trying to achieve.

To use gas from an external bottle plugged into the BBQ port in preference to the underslung tank supply, I think you would have to isolate the latter using the big brass knob under the cover plate on the tank itself. Otherwise the gas could be drawn from one or both open sources of supply, and you would have no control over which one was being used.

It also seems obvious that in order to use a Gaslow adapter plugged into the LPG fill point, the underslung tank would have to be empty. You can't get bottles of higher pressure, so the gas would not flow from the bottle into the tank until the tank pressure was significantly lower - i.e. empty. This system would undoubtedly work, but it would not achieve the objective of the OP - i.e. to use gas direct from the bottle in order to reserve the contents of the underslung tank.

(When filling from an LPG pump at a garage, the word "pump" is significant. The LPG is force pumped in as a liquid, rather than being transferred as a vapour from a higher to a lower pressure container - as would happen with the Gaslow adapter.)

LPG is a mixture of mostly propane with some butane, and bottled gas is pure propane, but that would not matter. The bulkhead regulator will cope with either, and if using a bottle plugged into the BBQ point it would have an appropriate bottle top regulator fitted to reduce the gas pressure before feeding it into the system.

I think this information is correct, but as ever . . . . . . the caveat! 

Hope it helps.

Caveats in force: I did a test on mine yesterday to check that the external bottle could supply sufficient flow for all the gas appliances. Only switched off the regulator on the underslung tank as that isolates the supply from that tank.
So, a very cold propane cylinder a third full with a standard regulator and plugged in to BBQ socket. Lit all hob burners and then fridge, water and cabin heat, grill and oven all on full chat. Hob burners still fine so happy external bottle will have sufficient flow for all scenarios 

Yep - exactly what I would have expected Jaytee. Thanks for the practical info. 

I believe the latest vans don't have an isolating switch on their regulators as they are the Secumotion type, in which case they would have to use the big brass knob under the cover. I might be wrong - someone with a new van will no doubt advise.

A minor detail however, which has no effect on the overall scenario.

Jaytee wrote:Caveats in force: I did a test on mine yesterday to check that the external bottle could supply sufficient flow for all the gas appliances. Only switched off the regulator on the underslung tank as that isolates the supply from that tank.
So, a very cold propane cylinder a third full with a standard regulator and plugged in to BBQ socket. Lit all hob burners and then fridge, water and cabin heat, grill and oven all on full chat. Hob burners still fine so happy external bottle will have sufficient flow for all scenarios 

Much better to know it does work than to spend hours theorising - thanks John.

Oooh, I don't know Peter.

During the vile winter weather I can spend many a happy hour theorising about our next holiday to France.

Then when we hit French soil the carefully laid plans usually last at least two days!!!    

Gromit wrote:Oooh, I don't know Peter.

During the vile winter weather I can spend many a happy hour theorising about our next holiday to France.

Then when we hit French soil the carefully laid plans usually last at least two days!!!    

That different, more art than engineering.

Thanks for all the replies. I think I will be isolatng the onboard tank and supplying gas via the bbq point from an external bottle fitted with an appropriate regulator.

Hi Ray

I don't know if this would be any use.

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