Our professors in the university teach us that critical value of moisture on the last stage of the steam turbine is 16% (no more) . You can find reference on that fact in the book:"Зайцев. Ю.И., Юрий Иванович. Основы проектирования судовых паровых турбоагрегатов. - Ленинград: Судостроение, 1974. - 439 с."