Conduit joint

Abstract

Each section of a conduit has a male pipe thread formed on its outer wall surface at one end. The other end of each conduit section has a short length of decreased outside diameter extending axially inwardly with a decreased axial passageway through the reduced diameter length. A sloping annulus is formed between the length of decreased outside diameter and the remainder at the conduit section. The other end is flared and has a flat end face substantially perpendicular to the longitudinal axis of the conduit section. A coupling sleeve has an annular flange at its axially inward end which defines a central opening such that the coupling sleeve may slide freely to a limited extent over the length of decreased diameter of the other end of the conduit section. The axially outward end of the coupling sleeve has female machine threads formed thereon. Intermediate the inner surface of the flange and the threaded portion is a sloped shoulder. The coupling sleeve is retained captively on this other end by the interaction of the flange with the sloped annulus and the sloped shoulder with the flared end of the conduit section. The axial extent of the short length of decreased outside diameter is such that when said flange abuts the sloped annulus the end face of the coupling sleeve does not project beyond, e.g., is at least flush with the associated end face of the conduit section.