INTERNAL PIPE MARKING-OFF DEVICE OF POLISHING TRUCK

Japanese Patent JP3798903

B2

PROBLEM TO BE SOLVED: To form a marking-off part on the inside surface of an existing piping and perform an efficient repair welding by providing a marking-off member and a lifting machine for raising and lowering it in the pipe radial direction of the existing piping. SOLUTION: A marking-off member 5 has a function of carving a marking-off part Pa in contact with the inside surface of an existing piping P, and it has a blade part 5a for carving Pa formed on one end part. The other end part is engagingly fixed to one end part of a piston 6a provided in the cylinder unit 6 of a lifting mechanism. The lifting mechanism is a mechanism for raising and lowering the marking-off member 5 in the pipe radial direction of the existing piping P, which is formed of the cylinder unit 6 and a control mechanism. The control mechanism is provided within a case member 1A to control the rising and falling of a Z-axial moving mechanism 40. The repair welding of a weld defective part WP is executed with the marking-off part PA carved on the inside surface of the existing pipe P by the marking-off work as a mark.