Abstract: A method of cutting and removing a section of prestressed concrete cylinder pipe and then installing a replacement valve while the pipeline is fully pressurized uses a replacement valve body (22) with two cylinders (223, 225) that match the openings of the cut pipe (35). Inside each of the two cylinders (223, 225) is a cut-covering assembly (62) which includes a cylindrical elastomeric seal (26) and spring tube (25), and a cross brace (27) extends between two surfaces within the spring tube (25).

Abstract: A method of cutting and removing a section of prestressed concrete cylinder pipe and then installing a replacement valve while the pipeline is fully pressurized uses a replacement valve body (22) with two cylinders (223, 225) that match the openings of the cut pipe (35). Inside each of the two cylinders (223, 225) is a cut-covering assembly (62) which includes a cylindrical elastomeric seal (26) and spring tube (25), and a cross brace (27) extends between two surfaces within the spring tube (25).

Abstract: A valve assembly includes a valve body with an access opening in which a linearly installed but pivotally operated gate-like valve-stopping mechanism is disposed, said mechanism including a support structure or cartridge with a pivotally moveable valve-stopping element or isolator (e.g., a butterfly element). A method for hot tapping a pipeline with a valve assembly as described above proceeds by (i) connecting the valve body to a line to be tapped, (iii) connecting a hot-tapping machine to the valve body, (iv) connecting a bonnet holding the valve-stopping mechanism to the valve body over the access opening, (v) hot tapping the line, (vi) advancing the valve-stopping mechanism into the valve body interior, and (vii) disconnecting the hot-tapping machine from the valve body with the valve-stopping element pivoted to the first position where it stops fluid communications. The gate-like valve-stopping mechanism can replace a gate in an insert valve (IV) or a repair-under-pressure (RUP) valve.

Abstract: A valve includes a valve body with a hollow valve body interior and an opening-defining portion that defines an access opening. The opening-defining portion is arranged as a connection-facilitating structure for facilitating the fluid-tight connection of a separate isolation valve assembly to the opening-defining portion in a position over the access opening that enables removal and replacement of a valve-stopping mechanism from the valve through the isolation valve assembly. It may include a flange, exterior thread, one or more annular grooves or rings, and/or a segmented cam lock arrangement.