| 摘要 |
The valve includes a first rod having a smaller dia., a second rod located below the first rod having a larger dia., a third rod located below the second rod having the largest dia., and a fourth rod located below the third rod having a reduced dia. in comparison with that of the third rod. A top end of the first rod is formed with a conic shape. An annular shoulder is formed between the first rod and the second rod, on which teeth-like grooves are provided. Another annular shoulder is formed between the second rod and the third rod, which is inwardly recessed to form an inwardly recessed annular groove. An outer peripheral surface of the third rod is provided with axial liq. introduction grooves. |
