APPARATUS FOR DIAGNOSING CAPACITY OF VALVE IN OPERATING

摘要

PURPOSE: An apparatus for diagnosing the capability of a valve in course of operation is provided to secure the safety of the valve in course of operation and confirm soundness. CONSTITUTION: An apparatus for diagnosing the capability of a valve in course of operation includes a strain gauge measuring strain change rate applied to the valve as electric resistance change rate, a strain gauge processing part(1A) balancing the electric resistance change rate and amplifying signals, an LVDT(Linear Variable Differential Transformer)(2) detecting position of a valve stem and converting displacement rate according to the electric resistance change rate into electric signals, a load cell(3) outputting a force sensing signal to detect the operational state of the valve, a limit switch and a torque switch(4) driving or stopping a MOV(Motor Operated Valve) and stopping the valve, a current sensing part(5) detecting operation current of the MOV, a motor apply voltage sensing part(6) detecting voltage applied to the MOV to obtain line voltage, a switch signal processing part(11) outputting a switch signal to a signal interface part(13), a transducer(12) outputting watts output obtained by firstly amplifying, multiplying, and synthesizing a driving voltage signal and a driving current signal of the MOV, and secondly amplifying the synthesized signal, and the signal interface part receiving voltage signal, current signal, watts output, and motion signals for converting into analog signals, and converting into digital signals through a process control interface card(20) for performing data interfacing with a PC.