Depending on the size of the compressed air cylinder, 2 to 3 cubic metres fit into it. This is then somehow equal to the volume of a telephone booth. Normally, there is about 180-200 bar in a tank. Thus if a 10-litre tank is filled with 200 bar, then this corresponds to 2,000 litres of air.
What types of compressed air cylinders are there?
For diving, cylinders with 200 and 300 bar pressure are permitted. These are mostly made of aluminium or steel, so that they can withstand the pressure without bending. The advantage of aluminium is thereby that the material itself is light. However, they are significantly bigger, since aluminium needs a thicker wall in order to withstand the pressure. In addition, aluminium has a higher buoyancy, so that you might need to take more lead weights with you. This is why steel cylinders are still the most popular choice.
Safety of your compressed air cylinder
Steel cylinders have to be subjected to an extensive security test every two years, aluminium cylinders every 6 years. Thereby an expert tests whether the cylinder is damaged inside and how much pressure it can still withstand. In doing so, a 200 bar cylinder must withstand 300 bar and a 300 bar cylinder 450 bar.
You should always transport filled compressed air cylinders horizontally, never vertically! If a standing cylinder falls, the pressure can escape explosively. Moreover, the cylinders must be specially secured during road transport.
You can only fill compressed air cylinders when they are standing and with a compressor authorised for it.
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