Model Balloon Fuel Cylinder
The model balloon fuel cylinders are maid only for propane and butane liquid gas mixtures to be used in model hot air balloons and model hot air airships.
Always wear suitable gloves when handling liquid gas as vaporising liquid gas
can become extremely cold.
If liquid gas mixes with air, highly explosive mixtures can be created.
Therefore keep away all sorts of ignition when handling or filling model
balloon cylinders and only fill the cylinders outside of buildings on the air.
There are two kinds of cylinders:
- Type A #00 2100 liquid brass coloured main valve, for the main burner, with dip tube for liquid gas
- Type B #00 2300 liquid and vapour brass coloured main valve, for the main burner, with dip tube for liquid gas + chromed main valve, for pilot light, without dip tube for liquid gas
The cylinders have a 1/8" external thread and an M5 internal thread. The cylinders type A are connected to each other. Usually three liquid cylinders type A are on the right side of the basket, and two are on the left side of the basket. On the left side there is an additional cylinder type B feeding the pilot light.
There is a safety valve installed in each cylinder. It opens at 18 bars +/- 10 % and closes again when the pressure drops down.
Do not unscrew the fuel cylinders head as the cylinder head is made from aluminium and the thread may break and it is not possible to repair it. All guaranties will expire if you manipulate or unscrew the cylinder or parts of it.
During the refilling you have to make sure not to overfill the cylinders. Connect the filling tube to the fuel cylinder you want to fill from (big balloon cylinder or camping cylinder upside down to get liquid gas) to the model balloon cylinder you want to fill. Make sure that the O-rings for sealing are in place.

If you use a camping gas cylinder for refuelling, the camping cylinder has to be used upside down to get liquid gas out of the cylinder.
In fuel cylinders for hot air balloons, there is already a dip tube installed.
Then you have to open the bleeding valve, the main valve of the model balloon cylinder and the ball valve of the filling tube. Now refilling can start.
As soon as liquid gas (white steam) comes out of the bleeding valve refilling has to be stopped immediately. Only by doing so you can ensure that there is enough room for the gas to expand when the temperature is changing.

Section through the cylinder. The bleeding valve will release liquid gas when 80% of the volume is filled. That gives the cylinder enough space to expand under normal conditions.
Attention !
If you overfill a cylinder, the cylinder can explode or the safety valve could open and gas leaves the cylinder unattended, creating an explosive mixture.
Filling has to stop immediately when liquid gas (white steam) comes out of the bleeding valve. To stop refilling you have to close the ball valve of the refilling tube first, then the valve of the model balloon cylinder and then the bleeding valve. If you have overfilled the cylinder by accident, you have to leave the bleeding valve open up until only vapour gas comes out of the bleeding valve. Be aware that this can become very cold as the liquid gas will vaporize
When connecting the refuelling line to the cylinder line, you have to make sure, that the O-ring is in place. Otherwise the line will leak and liquid gas will escape.
When the fuel line is connected, all lines should be closed first.
When the fuel line is connected, you can open the ball valve of the refuelling line. Then the bleeding valve has to be opened and afterwards the main valve of the fuel cylinder.
If liquid gas comes out off the bleed valve, filling has to be stopped immediately.
Therefore the ball valve has to be closed, then the main valve of the fuel cylinder and afterwards the bleed valve.
With this procedure you have to refuel every single model balloon cylinder, one after the other. If you use the combi fuel cylinder of type #00 2300 you have to note the following:
When you want o disconnect the filling tube from the model balloon cylinders it is necessary to open the drain valve of the filling tube. All other valves have be closed before. Then the remaining gas from the connection tube will be released from the tube and you can disconnect the cylinder from the filling pipe without getting cold fingers. Close the drain valve when you have disconnected the cylinders.
Filled cylinders may never be exposed to direct sun light. They have to be protected from direct sun light as the pressure will otherwise increase and liquid gas can be released unattended, creating an explosive mixture. Cylinders can only be stored inside buildings, garages, cellars or basements when they are completely empty.
Important Note for combi fuel cylinder type #00 2300!
As the combi fuel cylinder feeds the pilot lights, the pressure inside the combi cylinder is lower than the pressure in the other connected cylinders. As a result the other cylinders can fill and even overfill the combi fuel cylinder. For this reason it is useful to start burning from the side where the combi fuelcylinder is connected to. If the cylinder is overfilled it can prevent the pilot light from working properly. After the flight the fuel cylinders have to be checked if they are overfilled and liquid gas has to be released if necessary as the pressure "cushion" is not big enough and the cylinder may explode.
If you have any questions, don't hesitate to contact us.
Gentle Winds and Happy Landings!