DEVICE FOR TESTING MOVABILITY OF VALVE PLUG

摘要

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.