For all bottled gases, the volume of gas stated for each cylinder is the volume the gas will occupy at atmospheric pressure. For example, a 34 litre cylinder has an actual (water) volume of approximately 1 litre, due to the gas being so compressed and a 110 litre cylinder has an actual cylinder volume of approximately 1.6 litres. If using the bottled gases to fi ll rubber or latex balloons, due to the surprisingly large volume of a balloon (e.g. a 9”/23cm spherical balloon would have a volume of approx. 6.3 litres) and also the pressure the balloon walls exert on the gas, the number of balloons which can be fi lled will be considerably less than expected - probably only 3 or 4 from a 34 litre cylinder (depending on the size of balloon) and perhaps only 1 from a 14 litre bottle.