Abstract: A coupling assembly having an annular coupling with internal threads having a continuous plastic, corrosion-resistant coating. Opposed tubes are provided with a similar internal coating. The tubes have external threads inserted into the coupling with the internal and external threads being in threaded engagement. An annular gasket is provided of rigid material and is mounted between and in sealing engagement with opposed ends of the tubes within the coupling. The gasket has a continuous radial portion extending between the opposed ends of the tubes and in spaced apart relation thereto. O-rings are in sealing engagement with the tubing ends and the continuous radial portion of the gasket. A pair of opposed flanges extend from opposite sides of the continuous radial portion of the gasket and are in sealing contact with an interior surface portion of the tubes.

Abstract: A coupling assembly having an annular coupling with internal threads in threaded engagement with external threads on opposed tubes inserted into the coupling. An annular gasket of rigid material is mounted between and in engagement with opposed ends of the tubes within the coupling. This gasket has a continuous radial portion extending between these opposed ends of the tubes and a pair of opposed flanges extending from opposite sides of the continuous radial portion and into contact with an interior marginal portion of the opposed tubing ends. Sealing is provided between the opposed ends of the tubes.