Applies to the refining of crude petroleum oils and the drawing off of the petroleum factions which are natural gas, ligroin, gasoline, kerosene, naphtha, fuel oil, lubricating oil and petrochemicals derived from natural or refinery gases or the cracking of petroleum. Applies to the recovery of gasoline from casing head or natural gases and reclaiming, recycling or rerefining used motor oil. Oil producing to be separately rated.