Diesel (#2 Fuel Oil) Diesel is distilled from petroleum and is typically used in heavy equipment as fuel. While it is thin diesel is somewhat lubricating. It is typically handled in a bulk transfer application or on back-up generator skids. 4195 Cast iron Pressures up to 250 PSI Capacities to 580 GPM SG Ductile Iron Pressures >200 PSI Capacities to 190 GPM UL Listed 432-X Cast iron Pressures up to 100 PSI Capacities to 30 GPM UL Listed