Patent ID: 7641241

Claim:
A pipe joint between two metallic pipes which have been internally and externally coated with a material to prevent corrosion, said joint comprising: a spigot disposed on a first of said two metallic pipes; a socket disposed on a second of said two metallic pipes having an internal circumferential groove; an elastomeric sealing ring disposed in said groove; a lip disposed along said socket and extending from said groove to an end of said socket, said lip providing a welding location remote from the sealing ring, said end of said socket not being coated with said material to prevent corrosion; a heat sink member to disposed on said spigot, said heat sink member being a metal band with a substantially rectangular cross-section attached to and extending circumferentially around said spigot, said heat sink member configured to enable welding of said socket end without causing a critical rise in temperature of an inside surface of at least one of said metallic pipes; a weld joint region disposed along said socket between said lip and said welding location, said weld joint region formed in an area between a portion of said lip, said heat sink member and said spigot, said weld region being remote from the sealing ring wherein said sealing ring prevents fluid from entering the weld joint region; and a weld connection the lip to the heat sink member at said welding location.