Apparatus and method for bending insulated piping

A pipe bending machine (10) is described which incorporates a bending die (14) which supports coated pipe during bending without damaging the coating. In one embodiment, the bending die (14) employs a conventional die (30) with a plurality of longitudinal rods (40, 42, 44) spaced from the inner surface of the die (30) and in pipe confronting relation. When the pipe is urged against the bending die in the machine, the rods precompress the material thereunder for transmitting the bending forces. The rods (40, 42, 44) are spaced a sufficient distance from each other in the transverse direction about the inner surface of the die to permit the material to flow outward therebetween to reduce the stresses in the coating. In a second embodiment, a plurality of transversely extending rings (62, 64 66) are positioned on the inner surface of a conventional die (30) which further act to support bending forces without damage to the coating. In a third embodiment, a series of rods (106-114) are radially supported within a bending die (80). The rods may be moved radially inward to compress the coating material thereunder to support the bending forces.