SEARCH Articles Figures Tables Nutter float valves in open and closed positions for use on distillation trays. Used by permission, Nutter Engineering, Harsco Corp., Bui. N-2. [Publishers Imprint] See Also: Nutter float valves in open and closed positions for use on distillation trays. Used by permission, Nutter Engineering, Harsco Corp., Bui. N-2.