Abstract: A self-sealing pipe thread provides a connection for internally pressurized PVC pipes without the necessity of using sealant, O-rings, or gaskets. The thread holds pressure inside of the pipe and does not let gas or liquid to come in contact with any of the other threads. The sealing thread is provided by the tangential intersection between a flat annular sealing surface integrally formed on the head of the inside pipe thread and an annular line edge defining the inside edge of the ring step on the base of the outside pipe thread.