a seismic coupling is provided for coupling a first longitudinal section of plain end plastic pipe to a second longitudinal section of plastic pipe . the coupling is provided in two halves with a left half being initially installed on the plain end of the first section of pipe . an internal shoulder is fused onto the first section of pipe and a right half of the coupling is then fused onto the left half to capture the first end of pipe within the coupling . the second pipe end is then installed within an end opening of the coupling and held in position by a connector installed between the right half of the coupling and the second pipe end . internal seals are provided for sealing the first and second pipe ends within the interior of the coupling .