| 摘要 |
<p>PURPOSE:To restore a smooth condition in case an uneven surface is formed at a pipe inner surface using a shunt-off valve of screw-in type by means of machining-off of the uneven surface part. CONSTITUTION:A male threaded part 4 is formed at the peripheral surface of a column 6. and a seal ring 5 is fited on that peripheral part other than where the male threads are provided, and a machining cutter 60 to cut the pipe inner wall is mounted at the tail of the column 6, and a rotational operating part 6a to make rotational operation of the column 6 is furnished at the tail of the machining cutter 60.</p> |
