Abstract: The invention concerns pipe joints in which an improved locking segment has an outwardly extending protrusion which is adapted to abut a circumferential wall in the bell end of a pipe which telescopically receives a second pipe.

Abstract: A bell and plain end pipe joint are provided wherein the plain end has a raised portion on its outside diameter. A series of locking segments fit into a circumferential groove in the bell of one pipe and engage both the raised portion on the plain pipe and a portion of the bell. Upon an increase in fluid pressure in the pipes, the pipes tend to separate axially and the locking segments also contact and bear against a different portion of the bell. The joint provides a novel means of distributing the axial thrust tending to separate the pipe being joined.

Abstract: A friction reducing guide is provided as an insert in the metal gate of a resilient seated gate valve. The gate is encapsulated almost entirely with rubber except for the guide area. Friction is reduced and any corrosion resistant coating inside the valve body is protected, in the guide area, from excessive abrasion.

Abstract: An apparatus for determining whether an approximately circular opening falls within predetermined dimensions. A flexible circular gauge comprises two resilient cylinders, one partially encased inside the other. The outer diameter of the smaller cylinder equals the minimum designed diameter of the opening. The thickness of the outer cylinder is equal to one-half the predetermined tolerance in variation in the dimensions of the opening, and the entire gauge is sufficiently flexible to follow the inside walls of the opening even though they may depart from a precise circle.