Abstract: Structure and method are disclosed for providing timed valving in which a nutating plate having an opening defined therethrough moves relative to at least one other nominally static plate having a complementary opening defined therethrough, the nutating plate at one portion of the nutating travel bringing the opening defined therethrough in alignment with the complementary static opening and in another portion of the nutating movement positioning such opening therethrough in a spaced, sealing relationship relative to the complementary static opening. Either the nutating or nominally static plate may be utilized in pairs such that a sandwiched relationship between one type of plate and the other exists.