Two Oil Tanks Piping

Rookie

How would I repipe two oil tanks combo together, want to replace the feed piping single line inside house gravity feed tank setup, is there any code changes ( Massachusetts) to a two pipe system or is it ok to pipe the new lines using new copper and fittings from the bottom the same way is was done, I will add and extra filter at the burner and a osv valve, should i use a tiger loop?