Method and apparatus for testing the movability of valve plugs
AssigneeWestinghouse Electric Corp.
InventorRobert L. Osborne
Life of this patent
Estimating the term…
Abstract
A method and apparatus for testing the movability of a valve plug. The invention provides for movement of the valve plug from a first to a second position, from the second to a third position in an opposite direction, and again in the first direction to the first position. Indicators are provided to ascertain if such movements have occurred. Alarm signals are generated if any of the movements do not occur. The magnitude of the motions of the plug is normally small relative to the full valve stroke. Size of stroke and time at each position are chosen to minimize any disturbance to the power system.
Claims14
A steam turbine power plant comprising:
- a turbine;
- steam generating means for supplying steam to said turbine;
- an electrical generator driven by said turbine to generate electrical energy for a predetermined load;
- valve means normally movable between a fully open to a fully seated position for controlling the admission of steam into said turbine;
- means for controlling the position of said valve means in accordance with an electrical control signal;
- means for testing the motion of said valve means during the operation of said turbine without effectively disturbing the predetermined load, said testing means including
- actuator means for moving said valve means from a first to a second position in a first predetermined direction in response to a testinitiation signal from said control means,
- means for detecting the responsive movement of said valve means to said actuator means, and,
- means responsive to said detecting means for indicating that the responsive movement of said valve means has occurred.
In a steam turbine power plant having a steam generator element and a turbine, a valve connected in series therewith, wherein the valve having a seat and a back seat therein and a plug in a first position intermediate between the seat and the back seat, the improvement comprising:
- means for moving the plug from the first position to a second position in a first direction,
- means for testing whether the movement from the first position to the second position has occurred,
- means associated with said testing means for generating an alarm signal at times when the movement of the plug from the first position to the second position has not occurred,
- means for moving the plug from the second position to a third position in a direction opposite the first direction,
- means for testing whether the movement from the second position to the third position has occurred,
- means associated with said testing means for generating an alarm signal at times when the movement of the plug from the second position to the third position has not occurred;
- and,
- means for returning the plug to the first position from the third position.
A method for testing the movability of a valve plug comprising the steps:
- a. signaling an actuator to exert a force normally sufficient to move the plug in a first direction from a first position to a second position, and,
- b. generating an alarm signal if the movement from the first position to the second position has not occurred.
Dependencies are inferred from the claim text.