METHOD FOR MACHINING GRID-LINED, PRE-DIMPLED, DOUBLE-LAYER, MECHANICALLY LINED PIPE, AND LINING PIPE PREFORM

摘要

A method for machining a grid-lined, pre-dimpled, double-layer, mechanically lined pipe, and a lining pipe preform. The machining method comprises the following steps: step 1, manufacturing a preform of a lining pipe (2) matching an outer pipe (1) according to the shape and size of the outer pipe (1); step 2, calculating multiple pre-dimpling positions on the outer surface of the preform; step 3, inserting the preform into the outer pipe (1); and step 4, applying an internal pressure in the lining pipe (2), so that the preform can be integrated with the outer pipe (1), and small plastic deformation occurs to the preform around the pre-dimpling positions. Reinforcing ribs (3) are arranged on the outer surface of the liner preform according to a rule. According to the method for machining a grid-lined, pre-dimpled, double-layer, mechanically lined pipe, and the perform of the lining pipe (2), the contact structure between the lining pipe (2) and the outer pipe (1) is changed by artificially providing multiple periodically and regularly arranged critical flaws (3), such that irregular flaws randomly generated on the liner are avoided.