A pipe coupling is disclosed which is capable of being periodically coupled and uncoupled between two lengths of pipe. The pipe coupling includes a first and a second union which are fixed between an intervening length of pipe such that the intervening length of pipe does not have to be of a precision length. The outer periphery of one end of the pipe contains serrations and this end is fixed to the first union by a serrated compression ring and a backnut. By tightening the backnut onto the first union, the compression ring firmly engages the serrations on the pipe and prevents axial movement thereof. The second union includes a non-binding compression ring and a backnut as well as having an internal elongated bore of approximately the same diameter as the outer diameter of the pipe. As the backnut is tightened onto the second union, the compression ring is squeezed about the outer periphery of the pipe and forms a seal therewith. One benefit of this second union is that it can be repeatedly coupled and uncoupled relative to the pipe to permit the intervening length of pipe to be moved into or out of the second union as the need arises. The second union also permits a tight seal to be formed even when a limited amount of misalignment exist between the pipe and the second union.