Analysis of calibration error of NPP shut-off valve electric drive

The article describes the result of the research aimed at the development of a portable complex for carrying out rapid, non-disassembly diagnostics and calibration of torque limiters of motor operated valves at the place of their operation (multimedia training program). The concept and methodology of electric drive calibration at the place of its installation on the motor operated valves is described. The description of the software and hardware complex realizing this concept is given. The main test results of the complex which showed its applicability for motor operated valves diagnostics at NPPs are described. Statistical tests are performed in order to develop and certify measurement techniques. The uncertainty of the electric drive calibration result which is introduced by the calibration procedure itself is analysed. It is shown that the influence of torque sensor installed with the help of specially designed tooling between valve and electric drive is insignificant and affects only minor diagnostic parameters. Thus, the possibility of combining the operations of the basic drive testing and technical diagnostics of an electric drive has been confirmed. The obtained test results are used for the development and metrological certification of the methodology of direct and indirect torque measurement of the motor operated valves at the place of its operation