Cement-lined steel tube - has lining end contoured with radially outward part away from tube end to avoid interference with butt weld

摘要

The steel tube (1, 2) has an internal cement insulation layer (3, 4) which does not protrude beyond the end of the tube. The end of the layer is contoured such that its radially outer end is further away from the end of the tube than its radially inner end. The radially inner end of the cement lining may be flush with the end of the tube. The desired contour may be obtained by inserting a suitably shaped core in the tube end prior to the centrifugal cement application.