Lap joint stub ends are associated slip on flange in a piping system allows quick disconnection of the particular section involved. Stub ends are installed in pairs and mated together with two lap joint flanges. The surface of the lap joint stub end has a phonographic serrated gasket surface which prevents leakage at the joint. Using stub ends allows sections of the line to be opened for cleaning, inspection or quick replacement etc, without the need to re-weld. There lap joints stub ends are two basic types of stub end, A.S.A. long barrel, and M.S.S. short barrel. Under certain design criteria such as temperature or pressure etc., it is not acceptable to have the joint between stub end and pipe in close proximity with the flange joint; in these applications A.S.A. types are used.