Pipelines and flowlines that carry corrosive hydrocarbons are often protected by lining them internally with a thin layer of a corrosion resistant material. In the most economic method, the liner is brought in contact with a carbon steel carrier pipe by mechanical expansion. In applications involving severe plastic bending, such as winding onto a large diameter drum as is done in the reeling installation method, such a liner can wrinkle and collapse while the carrier pipe remains intact. Collapse has been shown to be sensitive to small initial geometric imperfections in the liner. A numerical framework for establishing the extent to which lined pipe can be bent before liner collapse was presented in [14–16]. This framework, suitably extended is used here to examine the effect of girth welds on liner collapse. The modeling starts by simulating the expansion process that plastically deforms the two tubes bringing them into contact. Bending plastically the composite structure leads to differential ovalization of the two tubes and detachment of the liner. The girth weld locally prevents this detachment creating a periodic boundary disturbance in the liner. With increasing bending the periodic disturbance grows and eventually yields to buckling into a shell-type diamond-shaped mode that causes the liner to collapse inside the intact outer pipe. The problem is investigated using a 12-inch carrier pipe base case. Comparing the collapse curvature of a girth-welded liner with imperfect liners free of welds that have the same collapse curvature, it is concluded that girth welds constitute a “weak” spot on the line. Results from a parametric study of factors that influence the collapse of a girth-welded are presented followed by recommendations.