In this phase a fully filled cylinder with the compressed gas is going to be under shot with a bullet having about 62.7mm to test the cylinder.

The bullet must penetrate completely at least from one side of the cylinder's wall. For CNG-2, CNG3, CNG4 the angle of the bullet hit must be about 45 degree.

The examination is acceptable when:

First: The cylinder doesn't break.
Second: the weight decrease shouldn't be more than 45 grams.