| 摘要 |
A butterfly valve includes a cylindrical body having substantially cylindrical inner bore. The bore is lined in its interior with an elastic seat in the form of a sleeve that terminates at the axial extremities of the bore. The sleeve has a substantially U-shaped cross-section that includes a face that is aligned with the bore and a valve spindle extending through the bore along substanially a diameter thereof and also extending through the sleeve. A butterfly is mounted in the body on the valve spindle. The body includes at least two annular grooves, each of which has an inner opening at the inner most end of the bore and is dosed at its outer most end. The grooves are coaxial with respect to the bore and open thereinto and are narrower at the inner most ends. |
