Katadyn Group

Approximate energy levels in different fuels

White gas: 10630 kcal/kg, 44,5 Mj/kg
Kerosene: 10270 kcal/kg, 42,9 Mj/kg
Diesel: 10290 kcal/kg, 43,1 Mj/kg
Aviation fuel: 10220 kcal/kg, 42,8Mj/kg
LP-gas: 11900 kcal/kg, 49,8 Mj/kg
Spirits: 7130 kcal/kg, 29,9Mj/kg

Gasoline/petrol stoves

If your stove is a gasoline stove, use white gasoline, Coleman Fuel, heptanes and similar as a first choice. In some countries ‘unleaded environmental gasoline is available and can be used as a second choice. Unleaded environmental gasoline is not the same as unleaded car gasoline. Environmental unleaded gasoline is a fuel designed for garden machines (i.e. lawn mowers) with four-stroke engines. It does not contain benzene and many of the other health hazardous additives that are put into car gasoline. Unleaded car gasoline contains a lot of additives that are needed for smooth engine operation etc, but these additives are extremely health hazardous and they are not burnt off properly when used in a stove. Instead, they escape as hazardous fuel vapour and exhaust fumes. Therefore, never use car gasoline of any kind for your stove!

How does it work?
Liquid fuel stoves

The fuel is pressurized by pumping (self-pressurized by heat during the priming in some gasoline stoves). Fuel then flows through the interior gas chambers of the preheated (primed) burner, where the liquid fuel is vaporized. The vaporized fuel is then forced trough the burner jet were it mixes with oxygen and the burns with a nice blue flame. Adjusting the flow of vaporized fuel that is forced through the burner jet controls output. The actual control of this flow is done by the spindle (the brass rod on which you apply the multi key / burner control key). The spindle is threaded in the burner house and as you open the spindle (turn the multi key to the left), it opens like a tap / faucet and vaporized fuel flows through the burner jet. Closing the spindle (turning multi key to the right) closes fuel supply again. The unique Optimus cleaning needle, that clears burner jets from the inside and out when using the stove, has teeth (cogs) facing teeth (cogs) of the spindle. The cleaning needle moves like a rack when turning the spindle. When you open the spindle (turn multi key to the left) the cleaning needle starts rising. When the spindle is turned to a full left, the cleaning needle clears the burner jet orifice. As the spindle is turned to the right again, the cleaning needle is retracted into the burner house. The cleaning needle arrangement on Optimus stoves is a prime feature. The risk of having unpleasant shutdowns when using the stove is reduced dramatically. And should the jet clog, the remedy is simple: a quick turn of the multi key to a full left will do the job. No need to turn off the stove, no upside down or shaking manoeuvres and no fiddling with prickers. Gas stoves Gas stoves use a blend of propane and butane gas contained in gas canisters of different sizes. Thanks to high pressure in the canister the gas is kept in liquid form. The liquid gas is very volatile and when you connect the stove to the canister and open the control valve the liquid gas vaporizes by it self and thereby feeds the stove with gas. Gas flow is restricted by the jet and after passing the jet the gas blends with air. The gas needs the oxygen in the air to burn with a stable blue flame. If air intake is restricted the stove will burn rich with a high yellow flame.

How much fuel do I need?

In summertime and if you intend to boil water and cook we recommend 0,1 litre (4oz) per person and day. In wintertime, if you need to melt snow, the consumption will be 0,2 litres (8 oz) and more per person and day. For gas stoves we recommend 60 grams gas (70/30 Butane/Propane) per person and day in summertime and 120 grams and more per person and day in wintertime. The consumption is only approximate and depends on what stove you are using, temperature, wind, altitude, humidity and much more.

WARNING!

Liquid fuels and gas fuels are extremely dangerous and should be treated with extreme care. The fuels are volatile and highly flammable. Always read special instructions that comes with the fuel or LP-gas canisters. Many fuel kinds (especially leaded car gasoline) are health hazardous. Inhaling leaded car gasoline vapour or getting car gasoline on your skin (e.g. hands) may result in cancer. We therefore advise you never to use car gasoline in a liquid fuel stove. 

Kerosene/paraffin and diesel stoves 

Use good quality kerosene/paraffin as a first choice. Use car diesel as a second choice. Kerosene/paraffin is generally available all over the world. It is an energetic fuel that will provide your stove with a good output. Kerosene/paraffin is not as volatile and flammable as gasoline. Consequently, it is a little bit less dangerous to handle than gasoline but it should still be treated with extreme care. On the other hand, longer priming is required in comparison to gasoline. Some stove manufacturers are a bit reluctant to recommend kerosene for use in stoves. Among other things it is stated that kerosene will result in frequently clogged burners. Provided that the fuel is of good quality and reasonably clean, this is not the case when using kerosene in an Optimus stove. The reason lies in the basic design of our burners where the vaporization process of a fuel is gradual and done in gas chambers. This ensures a thorough vaporization of the fuel in use, which may not be the case when using heavier fuels such as kerosene in stoves where the vaporization is done in generator tubes (refer to ‘Where Is the Generator Tube on an Optimus Stove?’ below). Diesel oil quality varies a lot with manufacturer and geographically. In some cases it may be too crude and/or too impure to be of good use in a liquid fuel stove. Good quality car diesel can in most cases be used. Marine diesel, on the other hand cannot always be used. This since marine diesel often is too crude and has a too high boiling/vaporization temperature in order to be vaporized properly by the burner of a liquid fuel stove.

Link to international site with fuel name

Paste this link into your browser: http://fuel.papo-art.com

LP-Gas stoves 

For LP-Gas stoves use only gas mixtures of 70 % Butane and 30 % Propane. Other mixtures or cartridges can make your stove overheated and may cause serious danger. There are many different cartridges of different brand available on the market. Quality of the cartridge and filling may vary. Optimus stoves are made for gas cartridges that comply with EN 417. LP-Gas is a very clean fuel with a high energy level. Running your stove on LP-Gas does not demand any priming or pumping and it will not leave any soot or smell.

Multi fuel stoves 

Never use car gasoline and especially not leaded car gasoline. Car gasoline is extremely volatile and flammable, but worst of all it is incredibly bad for your health. Use white gasoline or good quality kerosene/paraffin as a first choice. Kerosene is available in most countries in the world. It is an energetic fuel that will give good output to your stove. It is not as volatile and flammable as gasoline. Consequently, kerosene is a little bit less dangerous to handle than gasoline. On the other hand, kerosene requires longer and more thorough priming than gasoline in order to vaporize. White gasoline is generally a clean and energetic fuel suitable for use in liquid fuel stoves. Availability is good in North America. In Europe and other parts of the world, availability varies. Usually, you can find white gasoline in Outdoor shops. An alternative to white gasoline is heptanes that usually can be found in paint shops, hardware stores and similar.

Other fuels that can be used are: 

Car diesel provided that it is not too crude or dirty. If it is too crude, it will not vaporize properly in a stove. The result of improper vaporization is high, soothing and uncontrollable burner flame. Methylated alcohol/spirits. Meths is generally a clean fuel, but it is much less energetic than for example kerosene and white gasoline. All stoves must be converted to work off meths. The alcohol jet with a larger orifice must be fitted and air mixture must be reduced by fitting a restrictor tube or a slide valve. Fuel consumption is a lot higher when using meths in comparison to other fuels. Meths is on the other hand a good priming fuel since priming with meths does not soot as much as priming with other fuels. Environmental unleaded gasoline can be used provided that it is free of benzene and other additives (that are put into car gasoline). Environmental unleaded gasoline is usually sold as a fuel for garden machines (i.e. lawn mowers) with four stroke engines. Good quality colza/rapeseed oil. We can’t guarantee that colza/rapeseed oil will work. As with diesel, it is sometimes too crude to vaporize properly.

Where is the ‘generator tube’ on an Optimus stove? 

There are no generator tubes on Optimus stoves. This is one of the advantages of the design of the Optimus burners. On an Optimus stove, the vaporization is done in gas chambers inside the burner unit, whereas the vaporization takes place in the generator tube on many other stoves. When vaporization is done in a generator tube, the process itself is usually very instant and short. As a result, not all of the components of the fuel is vaporized properly. Instead carbon deposits are produced that eventually may clog burner jets and generator tubes. On Optimus stoves, vaporization is gradual in the interior gas chambers of the burner unit. Since vaporization is gradual, and gentle, vaporization is more efficient and you will have less (if any) problems with carbon deposits in your burner system.

Why does my stove flare up? 

1. Insufficient priming. Let the stove cool off and repeat the priming (never pour priming fuel onto a hot burner, it may Light explosively). In some cases, it may be sufficient to turn down the output for a while (running the stove at simmer) until the burner is hot enough to vaporize the larger flow of fuel that enters the gas chambers when stove is set at full output.

2. Different fuel kinds have been mixed. Never mix / blend different fuel kinds.

Why must a liquid fuel stove be primed (preheated)?

The burner of a liquid fuel stove must be primed (preheated) before use in order to vaporize (gasify) the liquid fuel. The combustion of a liquid fuel that has been vaporized is more efficient, and easier to control, than is the case with the fuel in its ordinary liquid form. When you are priming your stove, the mass of the burner house is heated up. With proper priming, the heat absorbed by the burner house is sufficient to make the fuel vaporize when it flows through the burner. Then, when the stove is started, the heat produced by the burner flame is sufficient to keep the vaporization process going as more fuel enters the burner.