Abstract: A pipe sealing gasket is shown which is designed to be received within a groove provided within a socket end of a thermoplastic pipe. The gasket includes a ring shaped body which, when viewed in cross-section includes a leading nose region and a radially inwardly slanting primary sealing surface which forms a lip seal for engaging a mating spigot end during insertion, the primary sealing surface being joined to a secondary sealing surface by an intermediate circumferential groove region, the secondary sealing surface comprising a planar circumferential region which terminates in an inside corner of the gasket, the inside corner being connected to an outermost wall region of the gasket by an exterior gasket surface, the outermost wall region of the gasket being connected to the nose region of the gasket by vertical step which joins a uniformly sloping external gasket surface.