Abstract: A corporation stop for use with standard tapping equipment includes a threaded stem with an enlarged, conical head for forming a blind side seal. A resilient sleeve member coaxially surrounds a narrow portion of the stem, and a flat compression ring rests coaxially above the sleeve member and has a notch formed radially in its outer edge. A standard saddle having a radially-inward tab is placed on the external sidewall of the conduit about the opening and receives the compression ring, the tab engaging the notch in the compression ring. A clamp nut is engaged with the threaded stem, forcing the compression ring against the resilient sleeve member to forcibly move the upper end of the sleeve member towards the compression ring to form an external seal between the compression ring and the external sidewall of the conduit and force the sleeve member over the enlarged, conical head of the threaded stem to form an internal seal within the lined conduit.

Abstract: A corporation stop has a threaded stem with an enlarged, conical head portion and a neck portion of reduced size coaxially surrounded by a resilient sleeve member. A flat, annular compression ring rests above the sleeve member and has at least one notch formed radially in its outer edge and has on its lower side a sleeve receiving recess of a diameter greater than that of the annular opening to receive the upper end of the sleeve member. A clamp nut is engageable with the neck portion of the threaded stem. A saddle member having at least one tab projecting radially engages the notch in the compression ring.