| 摘要 |
<p>PURPOSE:To allow a shut-off plug to move within a pipe without shutting off the distillation side of the pipe by squeezing-off etc. CONSTITUTION:A shut-off plug for a pipe is made by forming a male threaded part 4 at the tip of a column 6 and fitting a seal ring 5 thereon at its tail. The tip of the column 6 is formed tapered, and a rotational operating part 6a is provided at the tail, and a recess 6b is formed between the male threaded part 4 and the seal ring fitting part.</p> |
