Abstract: There is provided an apparatus for forming a weld joint between abutting ends of first and second tubular members. The welding apparatus includes a support ring defining an aperture therethrough. The support ring has first and second sides defining a channel therebetween. The first and second sides of the support ring define a plurality of supports spaced about the circumference of the support ring, each of which defines a gripping surface for contacting at least a portion of the exterior surface of a corresponding tubular member to thereby secure the abutting ends of the first and second tubular members at least partially within the aperture of the support ring. The welding apparatus includes at least one friction stir welding tool, which is movably and rotatably mounted within the channel defined by the support ring and projects toward the abutting ends of the first and second tubular members.