Locking plug for closing the sidewall of a pipe

For use in closing the internal cylindrical sidewall of a pipe, a locking pipe plug, comprising:

• a base member having a radial flange portion of diameter less than that of the cylindrical sidewall and an integral co-axial tubular portion;
• an annular elastomeric seal member having a circumferential sealing surface and a central opening slideably received on said base member tubular portion and in engagement with said flange portion;
• a circular rigid compression member having a central opening slideably received on said base member tubular portion, having a radial face in contact with said elastomeric member and having a frusto-conical circumferential surface extending in the direction away from said radial face;
• a plurality of rigid segmented slips circumferential received on said compression member frusto-conical surface and having teeth for biting into the cylindrical sidewall, the segmented slips being radially outwardly displaceable when slideably displaced on said frusto-conical surface;
• an actuation member slideably received on said base member tubular portion providing an end surface in engagement with said segmented slips;
• and
• a tightening nut threadably received on a threaded end portion of said base member tubular portion that can be threadably tightened to cause said segmented slips and said circumferential sealing surface to be outwardly displaced to lock the pipe plug in position and to sealably close the pipe cylindrical sidewall.