Patent ID: 6782344
Filing Date: 2004-08-24
Classification: F16K,G01M

Abstract:
A method for diagnosing abnormality and estimating degradation in a valve apparatus, comprising the steps of:connecting a torque sensor provided to a driving portion of a valve apparatus to a diagnosing apparatus, provisionally fitting current sensor for detecting an electric current to said driving portion and a vibration sensor for detecting vibration of said valve apparatus to said valve apparatus; converting detection signals outputted from said three kinds of sensors to predetermined signals in a data conversion unit; conducting an analytical diagnosing processing of diagnostic data information for each diagnostic item by referring to an allowance value of each diagnostic item calculated from the specification of said valve apparatus and set in advance, and to a maintenance record inclusive of the diagnostic result to judge whether said valve apparatus is normal or abnormal, said diagnostic data information including at least data about aptitude evaluation of torque of the driving portion, data about aptitude evaluation of seat force of the driving portion, data about aptitude evaluation of sliding drag of the driving portion, data about aptitude evaluation of time between opening and closing of a valve, data about aptitude evaluation of wear and loosening of said valve apparatus, and data about aptitude evaluation of a limit stop position of the valve; conducting further degradation estimation by conducting calculation with past diagnostic results, and preparing a future maintenance plan, thereby making it possible to conduct diagnosis from outside without opening and disassembling said valve apparatus and without cutting off the energy source even during operation of said valve apparatus.