Abstract: An improved seal system for the bell and spigot joint of a concrete pipe. The seal includes a bell sealing ring and a spigot sealing ring, each constructed of plastic material which when the spigot is received in the bell form a compression seal which will withstand substantial internal pressure without leaking. The ring members include, respectively, outwardly directed and inwardly directed ridges or flanges which are embedded in the respective bell and spigot ends of the concrete pipe. The spigot end ring, however, includes a central concave depression which extends into the concrete and receives an O-ring, and a lower depending flange also embedded in the concrete forming the spigot end. The joint of this invention then forms a reinforced concrete pipe capable of withstanding substantial internal pressure at least up to 50-60 pounds per square inch.