Abstract: A coupler for effecting hermetically sealed pipe or conduit interconnection by slip fit and without the use of tools. A coupler body member and a screw-on nut compress therebetween the outer marginal frusto-conical portion of a spring metal locking ring having arcuate segments directed angularly inwardly of the slipfit opening and defining a circle of slightly greater diameter than that of the pipe to be connected before the locking-ring is compressed in place, and slightly lesser in diameter than that of the pipe to be connected when the locking-ring is compressed in place. Pipe disconnect is accomplished by unscrewing the nut, which permits the locking ring to again assume a configuration wherein the arcuate segments define an opening of sufficiently greater diameter to permit withdrawal of the pipe.