Apparatus for forming plastic melts into strands or filaments wherein molten plastic material is delivered by a pump from a container through a feed line to a distributor means which has a first outlet for the molten plastic material to be processed and a second outlet to a return line leading back to the container, and a control valve is located in the return line to regulate the return of flow of the plastic material to the container, the return flow of the plastic material to the container, the return line and associated controls functioning to avoid undesirable plugging of the apparatus or damage to the plastic materials during interruptions in operations, and the like.