| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball valve having stable sealing performance while preventing the jump-out of or damage to a seat ring. <P>SOLUTION: The ball valve comprises a ball 14 having a through-hole 14a for opening/closing a flow path 13, the seat ring 17 provided on the fluid flow-in/-out side of the ball 14 for pressing against the outer peripheral face of the ball 14, and a seat retainer 20 for holding the seat ring 17 fitted into an annular seat ring holding groove 20a. It has a seal portion S<SB>2</SB>for sealing a space between the seat retainer 20 and the seat ring 17 with a bottom face 20a-1 of the seat ring holding groove 20a and a bottom face 17-1 of the seat ring 17, and a first space 31 located on the outer diameter side of the seal portion S<SB>2</SB>at a gap which is wider in inclination to the side of the ball 14 as tending to the outer diameter side. The first space 31 is deformed at the seal portion S<SB>2</SB>as a supporting point to absorb the thrust deformation of the seat ring 17. <P>COPYRIGHT: (C)2007,JPO&INPIT |
