Distillates (petroleum), C 3-6 , piperylene-rich; Petroleum gas (A complex combination of hydrocarbons from the distillation of saturated and unsaturated aliphatic hydrocarbons usually ranging in the carbon numbers C 3 through C 6 . It consists of saturated and unsaturated hydrocarbons having carbon numbers in the range of C 3 through C 6 , predominantly piperylenes.)