| 摘要 |
<p>PURPOSE: To provide a fluid flow closing device constituted so as not to generate various faults caused by dimensional differences in constituent parts. CONSTITUTION: The inflow zone 3 of a fluid flow casing passage starts with a mouth to a closing spherical body fluid flow passage with a smaller cross section than a closing spherical body fluid flow passage 6, and the closing spherical body fluid flow passage 6 starts with a mouth to an inflow zone with a small cross section than an outflow zone 4 of the fluid flow casing passage. A closing spherical body 5 meets respective requirements of being pressed against seating annular bodies 8, 9 under a spring force action. It is thus possible to obtain the closing device where a difference in the cross section between the inflow zone 3 and the closing spherical body fluid flow passage 6, and a difference in the cross section between the closing spherical body fluid flow passage 6 and the outflow zone 4 exceed a mismatch between these parts based on manufacturing and assembling tolerances.</p> |
