| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve stability and durability of a non-return valve by providing high gas tightness with simple structure. SOLUTION: The valve forms a recess or a projection in the vicinity of an inflow port, and a projection or a recess in the fitting section of the valve. The recess or the projection in the vicinity of the inflow port is engaged in the recess or the projection of the valve to fix the valve.</p> |
