Abstract: Plastic, such as polyolefin, pipe having a locking integral end connection. The pipe is fabricated with male and female end connections in order that the pipe may be press-fitted together with the interior and exterior forming a flush uninterrupted surface. One or more radial ribs and grooves are formed on the interior of the female connection while a registering series of ribs and grooves are formed on the exterior of the male connection. The ribs and grooves are of an interfitting axially extending wedge shaped configuration to provide a locking engagement to resist any tendency for separation. Interfitting corners of the ribs and grooves may be rounded to distribute stress and minimize damage when the pipe ends are fitted together.

Abstract: Polyolefin pipe having an integral end connection. The pipe is fabricated with male and female end connections in order that the pipe may be press-fitted together with the interior and exterior forming a flush uniterrupted surface. One or more radial ribs and grooves are formed on the interior of the female connection while a registering series of ribs and grooves are formed on the exterior of the male connection. The ends of the pipe are bevelled in order that the ends pressed together engage and by the slight resiliency of the polyolefin pipe construction permit the slight expansion and contraction of the ends to provide a locking interfit of the respective ribs and grooves in the two ends. The wall thicknesses of the end connection and width of the ribs and grooves are particularly dimensioned in order that the male end may be inserted to a complete lock position without premature engagement and that should failure occur, it be at the readily observable pipe wall rather than in internal rib.