LPG gas bottles types. Which ones are there?

What are LPG gas bottles and how do you use them? What differences are there?

You may be interested in LPG gas bottles because you want to use them in your camper, caravan, motorhome or food truck for cooking or heating, for example. Or maybe you want to use a gas BBQ in your garden or balcony or heat your patio or terrace with gas. In that case, it is useful to use a refillable LPG gas bottle, because then refilling is a lot cheaper. But an LPG gas bottle is also a lot safer thanks to the extra safety features such as the pressure relief valve.

In this article we tell you about LPG gas bottles and the different types such as; the material, type of gas tap and connections. We also explain the general operation and provide general safety advice. We will try to explain this step by step and illustrate it as best as possible. The associated topics are discussed further in additional posts.

LPG gas bottle as vapor gas bottle. How does that work?

Most LPG gas bottles are used as vapor gas bottles for cooking, for example. LPG gas bottles are filled with liquid LPG (Butane and Propane) and that is also stored in the gas bottle. But the gas is taken in vapor form (vapour gas). Because the gas bottles do not have an internal riser, the gas is taken from the top of the gas bottle, where the gas is in vapor form.

For this reason it is important that the gas bottles are always upright. Otherwise the operation of the gas cylinder will not be correct. (Both filling and gas consumption)

Because the vapor gas (which hangs above the liquid gas) is taken from the gas bottle, liquid gas will have to evaporate again and again to replenish the vapor gas and the pressure. This requires heat energy. The evaporation process removes heat from its surroundings. Propane evaporates slightly more easily at a low temperature than Butane. This means that when it is cold it will be more difficult for the gas to evaporate than in warm weather. The pressure in the tank is therefore highly dependent on temperature. So remember that if a lot of gas is used, the pressure in the gas bottle drops and this does not evaporate quickly in cold weather, which may mean that not enough can be supplied. In that case, it is sometimes better to use two gas bottles so that there is more evaporation capacity, or you can switch between the two.

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Reduce and adjust gas pressure

The pressure in the gas bottle varies from 1 to 20 bar (depending on the temperature), but this is in any case too high for the equipment you want to supply with gas (BBQ, burner, gas stove, etc.). It is therefore necessary to reduce (lower) the pressure to a constant low pressure. The standard pressure is 30 mbar. (For older equipment from before 2005 this may be 50 mbar.) This is done using a pressure regulator that you connect to the outlet of a gas bottle (directly or with a high-pressure connecting pipe or gas hose). Read more about this in the article about pressure regulators.

 Manufacturing equipment. What are gas bottles made of? And what are the pros and cons.

Steel Gas Bottles

Gas bottles have been made of steel since the beginning. Steel is a strong material and is easy to work with, making it easy to use to make a gas cylinder. The advantage of steel is that it allows for a cheaper construction, so the price can be lower. But it will also conduct heat energy better than, for example, plastic, allowing more evaporation to take place. The disadvantages are that steel is a relatively heavy material and can rust in the long term. Refillable steel gas bottles are often equipped with a 4-hole fitting system or equipped with a MultiValve gas tap.

Lightweight Plastic Gas Bottles

The big advantage of plastic material is its low weight. But the construction is more complicated and the production process is more difficult. A cylinder shape of composite fiber is first wound, called the “liner”. A plastic sleeve is then placed around this, which gives the gas bottle a base, handles and protection. The gas bottle is equipped with a tank tap (different types) for filling, removing and safety. The popularity of plastic gas bottles has increased significantly in recent years. Refillable gas bottles are available with an OPD gas tap or with a MultiValve gas tap.

Lightweight Aluminum Gas Bottles

Aluminum is also much lighter than steel and makes it possible to make a lightweight gas bottle. The construction of an aluminum gas cylinder is partly comparable to that of steel and therefore simpler than that of plastic. But the price of aluminum has increased significantly in recent years, making aluminum gas bottles more expensive than steel or plastic gas bottles. The big advantage of aluminum is that it is a very good heat conductor, which benefits the evaporation process in the gas bottle. A refillable aluminum gas bottle is usually equipped with a MultiValve gas tap.

Different Types of Gas Cylinder Valves

The main difference between a refillable and non-refillable LPG gas cylinder is the type of gas tap and the safety features on the gas cylinder.

For example, refillable gas bottles have an 80% fill limiter and a pressure relief valve that ensures that the pressure in the gas bottle never becomes too high. This makes a refillable gas bottle much safer than a regular gas bottle.

But there are also different variants of these safe gas taps and valves.

OPD Gas Bottles

An OPD gas cylinder valve stands for "Overfill Protection Device" which is equipped with a float and an 80% fill limiter as well as an overpressure valve. With this type of gas cylinder tap, LPG filling and gas consumption (vapor gas consumption) are done via the same entrance/exit. So there is only one connection on the gas bottle.

This type of hand tap has the following features:

- Hand tap for opening/closing the gas bottle

- A float with an 80% filling limit. (Overfill Protection Device)

- a pressure relief valve that does not allow the pressure in the gas bottle to become too high (26 bar).

- Common single connection for both filling and gas extraction: EN15252: G.12 = W21.8 x 1/14 (M22) Left-hand thread type SHELL connection with rubber sealing ring.

Read more about OPD Gas Bottles here

Image of OPD next to it

An OPD gas bottle therefore has only one connection that serves both for filling the gas bottle and for removing gas. Just like you refill a water bottle and then drink from it again.

You must therefore first fill the gas bottle, then remove the filling connection and then reconnect a pressure regulator (or intake line) to it. This is fine if, for example, you use the gas bottle in your garden, patio or on your balcony, so not necessarily in the vehicle where you fill the gas bottle.

MultiValve Gas Bottles

If you are looking for a gas bottle for a fixed location (for example in your camper or caravan) and you do not want to have to change the connection (from filling to taking off and vice versa), then using a MultiValve gas bottle may be a better option for you. This type of gas bottle has a separate entrance (with 80% filling stop) and a separate output to which you can permanently keep the pressure regulator or withdrawal line connected. Read more about MultiValve Gas Bottles here.

MultiValve: A gas bottle equipped with a MultiValve, on the other hand, has a separate entrance and exit. Here too, the filling inlet is equipped with a float with an 80% filling limiter and a one-way valve so that the gas cannot flow back out. The vapor gas leaves the gas bottle via its own outlet that is equipped with a hand tap so that it can be closed. In addition, a multivalve is equipped with a pressure relief valve for safety. And equipped with a content indicator (clock) that is connected to the float in the gas bottle.

Because this type of gas bottle tap has a separate entrance and exit, it is no longer necessary to reach the gas bottle to change connections after connecting the pipes.

This type of gas bottle has the following features:

- Separate own filling connection (1/2" UNF 19mm) with 80% float (filling limiter)

- a pressure relief valve that does not allow the pressure in the gas bottle to become too high (26 bar).

- Tank float with content indicator (clock)

- Hand tap for opening/closing the gas supply.

- Gas connection: EN15252: G.12 = W21.8 x 1/14 (M22) Left-hand thread type SHELL connection with rubber sealing ring.

Read more about MultiValve Gas Bottles here.

Image MV Gas bottle next to it

Type of connection on gas bottle output

In this article we discuss gas bottles and pressure regulators with a SHELL connection (W21.8 x 1/14 (M22) Left-hand thread). This is the most common connection to gas bottles in Europe. (Other types of connections are also used, such as the POL connection, but we will not consider this.) There are also different variants of the SHELL connection. The main differences are in the method of closure (G.5 / G.12) and the outside / shape of the union nut.

The G.5 type has no rubber seal on the gas bottle side and this part is made entirely of brass. In this case, the counter part (which is screwed onto the gas bottle) often has a rubber or plastic ring that provides the seal.

The G.12 type works slightly differently (or vice versa). For example, there is a recessed rubber ring on the gas bottle side, while on the other side there is a brass ring that is pressed into the rubber when tightening the coupling.

It is not possible to connect a pressure regulator (or gas hose) with a G.12 (brass ring) to a gas bottle with a G.5 connection (without rubber). In that case there is no gas seal.

But it is possible to screw a G.5 coupling onto a gas bottle with a G.12 connection. In that case, the rubber plastic sealing ring of the G.5 coupling will provide the seal.

If necessary, use an adapter / adapter to convert a G.5 connection on a gas bottle to a G.12 connection.

Image of gradient G.5 G.12 next to it

Image overview of different types G.5 and G.12

General safety advice for gas bottles:

- Always keep the gas bottle upright. (with the tap above)

- Do not drop the gas bottle, as damage may occur to the bottle or the couplings.

- Do not store the gas bottle near an open flame.

- Do not use or store below ground floor level. Leaked gas will accumulate at low levels.

- Gas bottles and pressure regulators often have a pressure relief valve, for this reason these parts may not be placed inside (the living space of) a camper or caravan. These should be used outside or in a ventilated area that is connected to the outside air and not connected to the indoor space.

- The storage must be well ventilated, preferably outside.

- Do not use tools to open the tap.

- Check the hoses regularly and see if the cylinder is properly secured. If the hoses are damaged or show signs of wear, replace the hoses (use the correct quality hoses)

- Use the NPR-2577 guidelines

DISCLAIMER

The information in this article is intended as an aid only. No rights can be derived from this article. The applicable laws and regulations (such as the RDW LPG installation requirements or NPR-2577 guideline) are always leading.

Please read our full disclaimer here.