ApplicationNo. 05/665822 filed on 03/11/1976
US Classes:137/551, WITH INDICATOR, REGISTER, RECORDER, ALARM OR INSPECTION MEANS73/168, BLOWER, PUMP, AND HYDRAULIC EQUIPMENT73/9, FRICTIONAL RESISTANCE, COEFFICIENT OR CHARACTERISTICS91/1, WITH SIGNAL, INDICATOR OR INSPECTION MEANS92/5RWITH (1) SIGNAL OR INDICATOR OR (2) INSPECTION WINDOW IN EXPANSIBLE CHAMBER WALL PORTION
ExaminersPrimary: Cline, William R.
Attorney, Agent or Firm
International ClassF16K 37/00 (20060101)
AbstractApparatus and method for indicating whether friction forces within a position modulating valve are approaching a predetermined friction value. The invention includes pressure detectors which monitor the pressure forces required by the valve actuator to move the valve plug predetermined distances toward open and seated positions. Means are provided which generate signal proportional to the difference between opening and seating actuating pressures and which is functionally related to the friction force within the valve. Means for comparing the generated signal to a predetermined reference signal, and for indicating if the generated signal exceeds the reference, are also provided.
Field of SearchFluid pressure responsive indicator, recorder or alarm