regulator

[Christopher_5130774]

Could any one please explain what the impact is of using a 28 bar camping gaz regulator as against a 37 bar regulator on calor gas. I am not suggesting that I use a camping gaz regulator on a butane bottle or vice versa.

Any other info on bar pressure would be appreciated.

Thanks

C

 

[Damian]

Camping Gaz is Butane and operates at 28mbar.

A 37mbar regulator is designed to work with Propane.

Butane gives a hotter flame and uses less gas than propane to heat a specified amount of water to the same temperature than propane.

Butane stops being effective at about 4 degrees, it stops gassing and hence, no gas supply.

Propane on the other hand is usable to about -40 degrees, but you use more gas to achieve the same heat.

Most appliances are made to burn quite safely on either 28mb or 37mb, and of course for vans fitted with the EN1949 required regulator, 30mb for both gases.

 

[RogerL]

Cylinder mounted regulators are 28mBar (not 28bar!) for all butane cylinders, whether Calor, Camping Gaz or any other. 37mBar is used for propane, regardless of supplier.

 

[Rubix]

How come many "appliances" that are connected directly to a camping gaz cylinder don't appear to need a regulator, wheras all calor cylinder appliances need a seperate reg

Do they have a reg intergrated into whatever you are connecting to the cylinder ?

There is an adapter for a camping gaz cylinder so you can use a calor 4.5kg butane reg. so is there a a difference between these appliances used ??

 

[ProfJohnL]

Hello Rubix,

There are a number of appliances that can be connected directly to a bottle of Camping Gaz. They do not need a regulator because they are designed to run at bottle pressure. They are generally appliances that do not need fine control, so the fact that the bottle pressure will change with temperature and use is not a major concern.

There are three important things to remember:

1,You must never connect a Butane appliance that does need a regulator directly to a bottle.

2, You must never uses a butane bottle pressure appliance on a propane bottle.

3, You must never use a butane bottle pressure appliance on a regulated supply.

 

[Rubix]

Thanks John, however I don't understand this comment :

"3, You must never use a butane bottle pressure appliance on a regulated supply."

Do you mean if the appliance doesn't need a reg, don't use one ?

If I had an appliance designed to be used from a butane cylinder with a reg, Should I still connect the reg to the adapter if I was using camping gaz (rather than a calor cylinder) ?

 

[Damian]

Rubix, the cylinder pressure of either gas is much more than the equipment in a caravan is designed to work correctly with, hence the need for a regulated supply, to ensure correct burn.

Putting cylinder pressure direct to a regulator dependent appliance will cause the flame to be very unstable, lift off the burner, and be far too aggressive, before going out and releasing unburnt gas into the living area, or through the exhaust vent, where any stray heat source would ignite it, with dire consequences.

Using camping gaz in a van still needs the gas to be routed through the regulator, which is why you can buy adaptors to connect gaz.

 

[rob_jax]

Rubix,

The gas inside a Calor Gas blue bottle and a Camping Gaz bottle is the same - Butane - so you treat them in exactly the same way.

If the appliance is designed to use a regulator - you must use a regulator.

Whereas if you use an appliance designed to work at bottle pressure (4 bar - 60 psig) and connect it to a regulated (30 milliBar - about 0.4 psig) supply - it's just never going to do anything - almost no gas flow

There are only a very few "bottle pressure" appliances available and they have HP (high pressure) stamped on them - usually a BBQ designed to screw directly onto the top of a Camping Gaz 907 bottle - so unless you bought a HP BBQ appliance, you always need a regulator

And to connect a Camping Gaz bottle to a caravan regulator - you need the adaptor.

Robert

 

[ProfJohnL]

Hello Rubix,

rob_jax has answered you query from my comment. A regulator will simply not supply enough pressure to run an appliance designed to run at bottle pressure.

The danger is that you may get a flame, but it will b very weedy (a very technical term!) and unstable. It might blow out without you knowing and that would release unburnt gas which is a very unsafe practice

 

[Christopher_5130774]

Hello John,

I started this thread, all I needed to know,is this the bbq I have indicates a 37 mbar pressure regulatoris used, if I use a 28mbar regulator (camping gaz) will the bbq still operate effectively ie will it cook my food. Could you advise please.

Thanks

Chris

 

[Guest]

Yes, it probably will. All new BBQ's are linked to the new patio style cylinders which are full of propane. All older BBQ's were linked to butane. It is a basically down to commercial practice. If the manufacturer can get you to buy a more expensive piece of kit then he is happy as he probably gets a backhander.

The patio cylinders supply a less amount of gas for a higher price...Gettit??

 

[ProfJohnL]

Hello Christopher,

You should use the type of gas and at the specified pressure indicated by that appliances data plate.

Whilst the vast majority of LPG appliances were rated to work with both Butane and Propane at 28mBar and 37mBar respectfully, if the manufacture has not specified Butane, then there is a chance that it might not work properly on Butane.

One consideration may be gas take off rate (or how much gas it uses). Butane bottles have a much lower capacity to sustain a high rate of gas usage than propane, and smaller bottles cannot provide the same high rates of take off that larger bottles can.

A fairly detailed explanation follows:

A new bottle of LPG (Liquefied Petroleum Gas) does not contain simply gas. It also contains liquefied gas. This is either Butane or Propane which has been pressurised enough to cause the gas vapour to turn into its liquid form. The pressure in the bottle is directly related to the temperature of the bottle. At 20C Butane will be at about 2Bar and Propane will be at about 6Bar. This is one of the significant differences between the two fuels. With no gas being used, the bottle will be dormant.

As soon as you use some gas, you have reduced the pressure a bit, and as a result the liquefied gas starts to boil and vaporises some of the liquid to replace the gas used. Just as with boiling a pan of water you need to add heat to keep the liquid boiling, and in the case of LPG bottles it gets it from the latent heat of the bottle and its contents.

Consequently when you use LPG, the bottle actually gets colder. How quickly this happens is dependant on the Gas Take Off (GTO) rate and the volume of the liquefied gas remaining.

As the bottle gets colder the vapour pressure drops, and eventually it will reach the point where there is no pressure to push gas out of the bottle. Normally the bottle will collect the heat it needs from the atmosphere, but if the weather is cold and/or the gas take off rate is too high, it is quite easy to cause a butane bottle to stop producing gas.

This is one reason why gas bottle should not be insulated, and why gas bottle lockers are well ventilated to allow the best access to the atmosphere to raise the bottle temperature when in use.

Exactly the same process applies to Propane, but because of its much higher vapour pressure, it will continue to gas off at much lower temperatures than Butane. Butane becomes ineffective at delivering gas at about 4C so that is why it is not recommended for deep winter use. Propane stops delivering at about -40C so there is much greater potential either at low temperatures or for large take off rates.

Your BBQ, may try to use more gas than the normal butane bottles can supply, which is one possibility that the manufacture may only rate it for Propane usage only.

Just as pointer on this Gas Take Off rate and bottle cooling, the next time you see either a roofer re-felting a roof, or one of the road white lining contractors working, you will note that they use propane, and that frequently the bottles have started to frost up at the bottom where the remaining liquid is.

It is also the case that the max 'GTO' of a bottle drops as the liquid level decreases. This is because the surface area of the liquid in contact with the bottle walls diminishes, and thus the ambient heat collection area also diminishes.