Calor to Gasit connection?

[in h]

Right. In that case how does the gas get into your system via the remote filler that you connect it to with this connector hose ?

Basically, there are two pressures for the gas.
The bottle pressure is the vapourising pressure of the liquid gas. That's usually from 10psi to over 300 psi*, solely depending on the temperature of the surface of the liquid. It is not dependent on the amount of gas in the bottle, though the temperature will drop dramatically as the liquid runs out.

The regulator takes this huge and varying pressure in, and puts out a very steady, low pressure of a little under 0.5psi
What you can do is add an external barbeque point to the side of the van. If the tank gas runs out, you connect the output of the regulator on the top of your bottle to the external gas point, so you feed the gas in backwards through the BBQ fitting.

There is no way that this could refill the tank: it can only supply gas for immediate use.

In theory, you could connect the high pressure output of the bottle to the fill point of the tank. As long as you have the bottle upside down as you do it, the liquid gas could flow down into the tank. I think it would work best if the bottle had been stored in a warm place for a few hours first.

In practice, this is a very dodgy thing to do unless you are very sure you know what you are doing. I once had a job topping up gas bottles for hire boats, and we used to be very careful to weigh them to make sure they weren't overfilled. That's not possible with an underslung tank.

*Most tanks have a safety valve set to release pressure at a bit over 400 psi, but I'm not sure that bottles do.

 

[channa]

Basically, there are two pressures for the gas.
The bottle pressure is the vapourising pressure of the liquid gas. That's usually from 10psi to over 300 psi*, solely depending on the temperature of the surface of the liquid. It is not dependent on the amount of gas in the bottle, though the temperature will drop dramatically as the liquid runs out.

The regulator takes this huge and varying pressure in, and puts out a very steady, low pressure of a little under 0.5psi
What you can do is add an external barbeque point to the side of the van. If the tank gas runs out, you connect the output of the regulator on the top of your bottle to the external gas point, so you feed the gas in backwards through the BBQ fitting.

There is no way that this could refill the tank: it can only supply gas for immediate use.

In theory, you could connect the high pressure output of the bottle to the fill point of the tank. As long as you have the bottle upside down as you do it, the liquid gas could flow down into the tank. I think it would work best if the bottle had been stored in a warm place for a few hours first.

In practice, this is a very dodgy thing to do unless you are very sure you know what you are doing. I once had a job topping up gas bottles for hire boats, and we used to be very careful to weigh them to make sure they weren't overfilled. That's not possible with an underslung tank.

*Most tanks have a safety valve set to release pressure at a bit over 400 psi, but I'm not sure that bottles do.

Back filling overall is a bad idea for it can interfere with any one way valves secondly running gas back wards through the native regulator does it no favours if there isn’t a shut off valve upstream

Gas bottles should never be used upside down,or on their sides ,the only bottles designed for side installations are those on a fork lift truck. They shouldn’t even be stored upside down when empty though you often see it the valves can and do leak one of the reasons even correct installation should never be near drains .lpg Heavier than air hence don’t want it sinking in watercourses should it escape

 

[Vanterrier]

Nick from Gasit further clarified two points regarding use of the hose...

"The bottle needs to be upright and used as you would normally.

You can connect it whilst there is gas in the tank but it won’t do anything until the gas tank runs out. Doing this when the tank is low is great becuase if the gas in the tank runs out over night the bottle will just take over and everything will work as normal."

K

 

[RV2MAX]

Look at "extenda stay" the yanks have done this with RVs for years

 

[in h]

Back filling overall is a bad idea for it can interfere with any one way valves secondly running gas back wards through the native regulator does it no favours if there isn’t a shut off valve upstream

Gas bottles should never be used upside down,or on their sides ,the only bottles designed for side installations are those on a fork lift truck. They shouldn’t even be stored upside down when empty though you often see it the valves can and do leak one of the reasons even correct installation should never be near drains .lpg Heavier than air hence don’t want it sinking in watercourses should it escape

How many motorhomes have one way valves in their gas system? Where are they, and why?
The gas can't go backwards through the tank regulator unless it is completely empty, which is very unlikely.
Nobody said you should use a bottle upside down, but that's the only way you can extract liquid and pour it into a tank.
Fork trucks, like LPG cars, take the LPG supply as a liquid, not a gas. That's why they have a different bottle or tank arrangement.

 

[Mr and Mrs Tupcox]

You can connect a Calor or any bottle to your external barbq point .as long as said bottle has a regulator. Most people on long term holiday site do this .

 

[channa]

How many motorhomes have one way valves in their gas system? Where are they, and why?
The gas can't go backwards through the tank regulator unless it is completely empty, which is very unlikely.
Nobody said you should use a bottle upside down, bit that's the only way you can extract liquid and pour it into a tank.
Fork trucks, like LPG cars, take the LPG supply as a liquid, not a gas. That's why they have a different bottle or tank arrangement.

In theory, you could connect the high pressure output of the bottle to the fill point of the tank. As long as you have the bottle upside down as you do it, the liquid gas could flow down into the tank. I think it would work best if the bottle had been stored in a warm place for a few hours first.

No one said you shouldn’t use a bottle upside down is it not yourself. Advocating that ?

A lot of vans ironicaaly have non return valves at the bbq point to prevent

backfilling , every manifold does too, running gas in the opposite direction to which it’s designed ....gas it , ,gaslow quoted here dont recommend backfilling for the the reasons given

 

[channa]

You can connect a Calor or any bottle to your external barbq point .as long as said bottle has a regulator. Most people on long term holiday site do this .

You can and people do, but that’s not to say it is recommended practice

 

[in h]

In theory, you could connect the high pressure output of the bottle to the fill point of the tank. As long as you have the bottle upside down as you do it, the liquid gas could flow down into the tank. I think it would work best if the bottle had been stored in a warm place for a few hours first.

No one said you shouldn’t use a bottle upside down is it not yourself. Advocating that ?

A lot of vans ironicaaly have non return valves at the bbq point to prevent

backfilling , every manifold does too, running gas in the opposite direction to which it’s designed ....gas it , ,gaslow quoted here dont recommend backfilling for the the reasons given

I'm sorry that you can't understand what I wrote. But you really have not grasped the meaning in the words I used. Perhaps someone else can explain it to you.

 

[UJ99]

Gaslow offers a similar product - the Reserve Cylinder Connection Hose.

https://www.gaslowdirect.com/Gaslow-Reserve-Cylinder-Connection-Hose

Provided that the external gas bottle contains propane, the high vaporization pressure of that gas will allow gas vapour to pass from the bottle through the non-return valve (NRV) of an LPG tank’s filler-hose, or through the NRVs in the filler-hose and internal bottle if the motorhome has a user-refillable bottle system.

The well-known “Extend A Stay” kit aimed at RVs requires modifications being made to the LPG tank

https://mobilervmaintenance.co.uk/product/extend-a-stay-kit

but that product, and the others discussed above, are always employed with the external gas bottle being upright.

People do decant LPG from one gas bottle to another (eg. from a large Calor bottle to a smaller one) by connecting the two bottles together with a hose, inverting the ‘donor’ bottle above the ‘recipient’ bottle and allowing gravity to cause the LPG to transfer. It would be a perverse thing to attempt in this instance and any NRV in the filler-hose and/or user-refillable bottle would prevent the transfer occurring.

 

[in h]

The well-known “Extend A Stay” kit aimed at RVs requires modifications being made to the LPG tank

https://mobilervmaintenance.co.uk/product/extend-a-stay-kit

but that product, and the others discussed above, are always employed with the external gas bottle being upright.

That is pushing Propane into the tank as gas, so it would only work if the tank was completely empty. However, if you turned the bottle upside down, it would transfer as liquid, and slowly refill the tank if there's enough pressure to open the non-return valve. I can see why they don't mention this: it's nether safe nor clever!

 

[cronkle]

Being a simple person who likes simple solutions I have to say I would not bother with one of these gadgets. If I anticipated that I would be in a position where I would need another bottle I would have a barbeque point fitted, buy any available bottle and a bottle-top regulator and go that route. One reason is that I would be messing around with the low pressure side rather than the high and a second is that the connector under discussion is only good for Calor bottles. A third reason is that I would then have a barbeque point that I didn't have to start with.

I'm sure there are plenty of reasons for me being wrong on this but then so would many other people.

 

[UJ99]

That is pushing Propane into the tank as gas, so it would only work if the tank was completely empty. However, if you turned the bottle upside down, it would transfer as liquid, and slowly refill the tank if there's enough pressure to open the non-return valve. I can see why they don't mention this: it's nether safe nor clever!

“...if there's enough pressure to open the non-return valve”.

When a motorhome’s LPG tank or user-refillable bottle system is refilled, the liquified gas is pumped into the tank/bottle at a pressure of up to 90psi. As this GAS IT webpage advises

https://www.gasit.co.uk/support/knowledgebase.php?article=17

a significantly high pressure is required to force open the fill-point and tank/bottle NRVs that the system must have to prevent gas from coming back out of the tank/bottle when the pump’s nozzle is disconnected.

As there will always be at least one NRV, the effect of gravity will be inadequate for liquid gas to flow from the inverted bottle into the recipient tank/bottle. The only reason that the gravity-powered ‘decanting’ method works is because the recipient vessel does not have an NRV.

 

[in h]

“...if there's enough pressure to open the non-return valve”.

When a motorhome’s LPG tank or user-refillable bottle system is refilled, the liquified gas is pumped into the tank/bottle at a pressure of up to 90psi. As this GAS IT webpage advises

https://www.gasit.co.uk/support/knowledgebase.php?article=17

a significantly high pressure is required to force open the fill-point and tank/bottle NRVs that the system must have to prevent gas from coming back out of the tank/bottle when the pump’s nozzle is disconnected.

As there will always be at least one NRV, the effect of gravity will be inadequate for liquid gas to flow from the inverted bottle into the recipient tank/bottle. The only reason that the gravity-powered ‘decanting’ method works is because the recipient vessel does not have an NRV.

You may be right. However, I suspect that if the propane in the tank is cold and the bottle has been in a warm room for a few hours, the pressure difference will be enough to force the liquid through. Still not a good idea, though.

 

[Okta]

“...if there's enough pressure to open the non-return valve”.

When a motorhome’s LPG tank or user-refillable bottle system is refilled, the liquified gas is pumped into the tank/bottle at a pressure of up to 90psi. As this GAS IT webpage advises

https://www.gasit.co.uk/support/knowledgebase.php?article=17

a significantly high pressure is required to force open the fill-point and tank/bottle NRVs that the system must have to prevent gas from coming back out of the tank/bottle when the pump’s nozzle is disconnected.

As there will always be at least one NRV, the effect of gravity will be inadequate for liquid gas to flow from the inverted bottle into the recipient tank/bottle. The only reason that the gravity-powered ‘decanting’ method works is because the recipient vessel does not have an NRV.

Not so sure. As soon as there is any lpg in the tank it will equalise the pressure between tank and bottle and the flow would stop.

 

[in h]

Not so sure. As soon as there is any lpg in the tank it will equalise the pressure between tank and bottle and the flow would stop.

That's not how it works. The pressure will depend on the surface temperature of the liquid in the tank, so if the bottle and its liquid/gas interface are warmer, it will stay at higher pressure then the cold tank.

 

[Wrighpm]

In my opinion these gadgets are aimed at making money. If you are keeping an eye on your gas management you will be much safer. Having "a backup" connected via a filling point, bbq point etc. NOT DESIGNED for cylinder connection is crazy. Save your pennies. I work for the fire service and can tell you your leaking LPG can travel like a river for a long way.....only to be ignited by a neighbouring bbq ! Some gadgets are brilliant...anything that messes with a gas connection should be given a wide berth. No offence intended

 

[SquirrellCook]

Propane is the most dangerous gas you can legally buy. When mixed with the correct amount air and detonated it will create a percussion wave you never want to experience. As part of a training course I was shown a video of a Ford transit being blown up. There was not much left. Stored propane has odd characteristics, it remains liquid due to pressure and temperature. It’s not like it’s very expensive, is it worth the risk to play with.

 

[UJ99]

In my opinion these gadgets are aimed at making money. If you are keeping an eye on your gas management you will be much safer...

The design purpose of the external hoses (GAS IT, Gaslow, etc.) that have been mentioned here is made plain from their adverts, with the products being described as offering a ‘reserve’ or ‘emergency’ gas supply capability.

If a motorhome’s habitation gas system does not include a LPG tank or user-refillable bottles, these products will have no benefit. And even if a motorhome does have a gas system based on a LPG tank or user-refillable bottles, in most European countries Autogas will be widely enough available to allow refilling of the tank/bottles well before they become empty.

Reserve/emergency hoses are nothing new and have been discussed in the past on many other motorhome forums. In December 2019 the owner of a motorhome with a 25-litre LPG tank said that he was planning to travel in Scandinavia in Spring 2020 and knew that Autogas-selling retail outlets were thin on the ground there and non-existent in Finland. He asked about having an external barbecue point installed (he had been quoted £250 for the task) to allow a ‘native' gas bottle to be connected to the motorhome, or whether purchasing a cheap portable diesel-fuelled heater might be a better alternative.

After various possibilities had been discussed at length, it was concludeed by the motorhome owner that obtaining the GAS IT reserve hose advertised here

https://www.gasit.co.uk/gas-reserve-hose-system-uk-21-8-lh-butane-type-nut.html

would be a sensible decision.

The owner had explained that he was wary of the accuracy of the contents-gauge of his vehicle’s LPG tank and that he already carried a UK 3.9kg propane bottle to fuel a barbecue. If the LPG tank did inadvertently run dry, he could - with the appropriate POL adapter - employ the GAS IT hose to connect the 3.9kg bottle to the LPG tank’s filler-point. And if that bottle also became empty while he was travelling in Finland, he should be able to use the GAS IT hose to connect a locally-obtained Finnish propane bottle to the tank’s filler-point.

Assuming that the motorhome owner does go to Scandinavia and is careful about gas usage and fully refills his LPG tank before entering Finland, it may well be that he would not need to use his 3.9kg bottle or a Finnish bottle as an emergency gas source. But if the tank did become empty in Finland and if he did not have the reserve hose and appropriate adapters, he’d have no gas until he left that country and was able to refill the LPG tank.

Lots of motorcaravanners have limited understanding of their vehicle’s gas system. But if a motorhome has a properly installed LPG tank or a properly installed user-refillable gas bottle system and the vehicle’s owner is practised in refilling that system with Autogas, there ought to be minimal safety risks if that person chooses to connect up an external gas bottle via an emergency/reserve hose.

 

[TR5]

The regulator takes this huge and varying pressure in, and puts out a very steady, low pressure of a little under 0.5psi
What you can do is add an external barbeque point to the side of the van. If the tank gas runs out, you connect the output of the regulator on the top of your bottle to the external gas point, so you feed the gas in backwards through the BBQ fitting.

There is no way that this could refill the tank: it can only supply gas for immediate use.

The use of the BBQ point is of course a valid and useful alternative for using an emergency bottle. However, it is very important to make the point that you MUST MAKE SURE you only do this through a regulator, you cannot connect it direct without one, and preferably one set at 30mbar as that is what modern motorhomes are jetted to. Also you need to make sure that there is no risk of the hose becoming damaged, detached, or fiddled with by unauthorised persons or pets, or the bottle knocked over. If you don't understand LPG installations, or don't know what your doing, take advice first, or leave well alone.

Whilst I can see the original poster (and I), know sufficient about gas installations to do this safely, I do cringe at some of the recommendations made regarding gas and electrical mods and/or fixes which, if in the wrong hands of someone with little or no knowledge of the subject, could be very dangerous.