The reason for the question is to harl back to the debate on "katastematic pleasure", which may may not be related to tranquility, and to ask whether indeed either or both of those terms is in fact a "sensual pleasure" at all. (This question is the theme of the Wentham essay in our files section.)
There is a question as to whether it is indeed "sensual pleasure" which establishes how Epicurus recognizes the good, and whether "absence of pain" describes an identifiable sensual pleasure itself, or whether it describes instead a condition in which other / sensual pleasures are experienced without any mixture of pain or disruption.