Cast Iron, IMHO, is only good for underground water and wastewater piping.
I will assume that you are installing this piping underground ....
Underground cast iron piping transporting crude oil, gas and other petroleum products in the USA is being phased out.
Properly coated steel piping will last longer, is tougher and will not fail catastrophically like cast iron when subject to excessive loading, frost heaves etc...
MJCronin
Sr. Process Engineer