Abstract: A molding apparatus for making a plastics pipe fitting or pipe coupling by injection-molding the plastics pipe fitting or coupling body, injection-molding at least one sealing ring separately but substantially simultaneously, and bringing the body and sealing ring together directly after the molding while these components are still in a hot as-molded state, so that a direct thermal bond is formed between them comprises respective injection-molding cavities for the body and sealing ring, and a reversible support for carrying the sealing ring out of its mold and into contact with the molded body. The respective molds are opened and the components are not stripped but are brought together for bonding while still in position on respective mold members, thereby eliminating intermediate handling and ensuring that the molded components remain clean and of accurate shape and dimension as they are brought together.

Abstract: Clay pipes and the like are fired in a kiln through which they are conveyed by a pusher conveyer as individual articles, instead of being carried on cars or in containers. In the main firing zone of the kiln the pipes roll along a surface to maintain roundness and ensure uniform heating. In the preheating zone of the kiln the pipes are carried by carriers of the conveyer without rotating. The pipes may also be carried without rotating in the final cooling zone of the kiln.

Abstract: Clay pipes and the like (3) are fired in a kiln (1) through which they are conveyed by a pusher conveyer (2, 4) as individual articles, instead of being carried on cars or in containers. In the main firing zone of the kiln the pipes (3) roll along a surface (6) to maintain roundness and ensure uniform heating. In the preheating zone of the kiln the pipes are carried by carriers (5) of the conveyer without rotating. The pipes may also be carried without rotating in the final cooling zone of the kiln.

Abstract: A pipe coupling formed by a tubular plastic member having at one end a portion of increased diameter defining an inwardly facing annular recess, and an annular sealing ring bonded therein by a foot portion substantially filling the recess and having a sealing head portion projecting partway across the interior of the coupling and secured to such foot portion by a neck portion. The seal ring configuration lends itself to injection molding of the assembly.