Abstract: A pipe coupling has an enlarged end for receiving a pipe end and a flange apertured for supporting coupling bolts; a tightening ring is placed around the pipe end and includes a slanted radially inner surface cooperating with a gripping ring; a slide ring is placed about the pipe end to be engaged by an end of the gripper ring; the enlarged end has a seal cavity with an inner slanted surface for engaging a seal ring; the gripper ring has two pairs of teeth extending radially inwardly to different extents with the axially inner pair being of greater length than the outer pair.