公开(公告)号：EP0115796B1

公开(公告)日：1990-07-25

申请号：EP84100420.3

申请日：1984-01-17

申请人： CRC-Evans Pipeline International, Inc.

发明人： Wheeler, Lionel Harris ,  Goekler, Robert Gerald ,  Luddeke, Daniel Guy

IPC分类号： B21D9/01

CPC分类号： B21D9/01

公开(公告)号：EP0115796A2

公开(公告)日：1984-08-15

申请号：EP84100420.3

申请日：1984-01-17

申请人： CRC-Evans Pipeline International, Inc.

发明人： Wheeler, Lionel Harris ,  Goekler, Robert Gerald ,  Luddeke, Daniel Guy

IPC分类号： B21D9/01

CPC分类号： B21D9/01

摘要： An internal mandrel (10) is disclosed which is used for supporting the inner wall (30) of a pipe (12) during bending. The internal mandrel includes a urethane plug (31) which is compressed between the piston (60) of a hydraulic cylinder (56) and an end plate (36). This expands the urethane radially outward into contact with the inner wall (30) of the pipe to support the pipe during bending. Resilient steel strips (88) can be mounted on the exterior surface of the urethane plug (31) at the inside bend of the pipe to increase the effective wall thickness of the pipe at the inner bend to reduce the likelihood of deformation during bending. In a second embodiment, internal mandrel (200) includes an annular urethane plug (204) positioned between a resilient cylinder (202) and the inner wall of the pipe (12).