摘要 |
<p>The annular body of a damper-type check valve has a mainly cylindrical inner surface that defines a fluid passage, but a ridge around it provides a valve seat that is inclined to the passage axis with its lower part forward in the direction of permitted fluid flow. The damper is dome-shaped, forwardly convex, and is swingable about a pivot axis which is parallel to its horizontal diameter but is spaced thereabove by about half its radius. A counterweight on the convex front face of the damper is concentrated near its geometrical center. A readily removable spring can provide supplemental closing bias on the damper.</p> |