O-ringless seal couplings

An operative fluid device comprising a fluoropolymer body portion and a fluoropolymer containment portion connectable to one another for containing the fluid at a fluid sealing connection with two frustoconical surfaces that first confront one another and then engage one another as the connection is made, one of the frustoconical surfaces being convex and the other concave, wherein when the surfaces are confronting one another before they are engaged they are angularly mismatched, and wherein the frustoconical surfaces first sealing contact is at a radially inward annular position on each of the frustoconical surfaces and proximate the interior, and as the mating portions are urged together, the sealing contact expands from the radially inward annular position radially outward to include majority of at least one of the two angularly mismatched frustoconical surfaces. Suitable annular structure including annular rings and annular recesses radially outboard from the frustoconical surfaces may provide radial con