Redundant regulation valve

摘要

The redundant regulation valve for controlling fluid flow comprises a valve body defining a passage for the flow of the fluid, a main throttle element movable by means of a main control device to selectively obstruct the passage, and a redundant throttle element movable by means of a redundant control device. When the valve is in its closed position in normal operation, the main element and the redundant element are in contact with each other. In this normal closed position, the main element is close to its fully-extended position in the closure direction and it obstructs only about half of the passage, while the redundant element is in a position of medium extension. The stroke of the redundant element is such that the redundant element can be controlled to obstruct the entire passage even when the main element is in its fully-open position.