PIPE SEALING METHOD

PROBLEM TO BE SOLVED: To facilitate welding by using a pipe end blocking member wherein wall thickness of a socket part is constant and suitable for non-filler TIG welding. SOLUTION: A blocking socket cap 1 composed of a blocking end part and a socket part is inserted in a cut part 3 of an existing pipe 2 as a pipe end blocking member, and then the outer face of the cap 1 is non-filler TIG welded by a welding torch 4 at the middle of an insertion part C of the cap 1 and the pipe 2. Thereby, the pipe is sealed by penetrating a cap welding part 5 into the pipe 2. The inside diameter of the cap 1 is preferably set, considering the outside diameter tolerance of the pipe 2 and the dross at the time of cutting the pipe 2. Also, thickness of the cap 1 is decided from the penetration depth of a weld zone regardless of the pipe diameter, and more concretely if the thickness is 2.5 mm under the non-filler TIG welding condition, secure penetration can be achieved.