Abstract: The present invention relates to a non-return valve that can be configured for use anywhere along a molding material flow path in a molding system. The non-return valve of the present invention includes an improved means to restrict the backflow of melt therethrough during injection. In particular, a spigot-seal is configurable, during injection, between overlapping, closely-spaced, and mutually parallel complementary male and female spigot portions that are configured between complementary valve members. The spigot-seal advantageously maintains an effective backflow restriction even in the eventuality of transient movement between the spigot portions during injection. Preferably, the non-return valve of the present invention is also configured to include a means for mutually aligning and/or guiding the complementary valve components that ensures a proper alignment between the complementary spigot portions, and may also serve to improve the function and longevity of a face-seal, when present.

Abstract: A method and apparatus for removing contaminants from the surface of a metallic article comprises a continuously flowing acid bath whose level of acidity and temperature is controlled and over which a purging gas flows to continuously remove hazardous gases generated during the removal of contaminants from the metallic article.

Abstract: The present invention relates to a static mixer for generating a substantially homogeneous media stream. The mixer has a series of angularly offset mixing elements with each element comprising a central boss portion, a plurality of ribs extending radially from the boss and defining with the periphery of the boss a plurality of substantially pie-shaped segments through which the media stream flows, and a plurality of webs for dividing each segment into two substantially equal flow areas. Each web has a first edge extending substantially radially and a second edge extending substantially circumferentially and is twisted through approximately 90.degree. from the first edge to the second edge.