LPG cylinders will come filled to around 80% of the height of the cylinder. This is normal as it allows for the expansion of the liquid LPG inside the cylinder. 

If you would like to test the level of LPG in the cylinder, the safe and accurate way is to:
  1. Pour warm water down the side of the cylinder
  2. Wait a few minutes
  3. Run your hand down the side of the cylinder - it will feel cold to the touch at the level of LPG.