摘要 |
<p>A fluid flow control device includes a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet. A valve seat ring is coupled to the body and defines an orifice through which the fluid flow path passes. A cage is also coupled to the body and defines an interior bore, wherein the cage includes at least one passage through which the fluid flow path passes. A throttling element is sized for insertion into the cage interior bore and movable along an axis between open and closed positions. The throttling element defines a sealing surface oriented substantially parallel to the axis. A seal is positioned to engage the sealing surface when the throttling element is substantially in the closed position, thereby to restrict fluid flow through the valve seat ring orifice.</p> |