| 摘要 |
<p>An annular valve seat is fitted in a rotary fluid control valve of the butterfly type. The seat consists of a radially outer tail portion (22), a radially intermediate metal support portion (30) in the shape of an S and a radially inner metal seal portion (40) having a metal sealing surface (44) in the form of an annular semi-torus. The seal portion includes structure for retaining an elastomeric sealing insert (50). The valve seat is inserted in a groove between the valve body (11) and an insert (16), with a small space existing between the axial sides of the groove and the axial sides of the S-shaped intermediate portion (30). The intermediate portion (30) accordingly permits limited flexure in response to pressure stresses on the valve seat, but the flexure is limited by contact with the walls of the groove. The metal and elastomeric sealing surfaces provide leak-free sealing with an extending life.</p> |
