How close can an oil tank be to a fence?

Close to liquid fuel appliance flue terminals. A wooden boundary fence is 760mm away from a non-fire rated boundary. 600mm away from the screening. It doesn't form part of the boundary.At 1.8 m of liquid fuel terminals. At 760 mm of a nominal limit without fire, like a wooden fence. Follow-up distance of 600 mm (e.g. trellis and leaves) which is not part of the limit.