An expansion nozzle for conducting melt from a floating manifold to a mold assembly comprises a bushing having a bushing flange and spigot having a passage therethrough joining a nozzle inlet and an outlet, a head having a seating surface and a bore through the head slidably receiving the spigot so that the spigot is movable relative to the head over a range from abutting contact of opposing surfaces of the head and bushing flange to a limit of axial separation of the opposing surfaces, axial separation of opposing surfaces of the head and bushing flange being maintained throughout an operating temperature range. Springs maintain sealing contact of a seating surface of the head with a mating surface of the mold assembly. Advantageously, a locating ring provides a reaction surface for the springs and supports the head to resist moments arising from axial misalignment of the expansion nozzle and mold assembly.