The application discloses a kind of in-service gas tree
valve stem defect detection method and
system, it is related to
ultrasonic testing technical field, comprising the following steps: making
valve stem simulation test piece with defect characteristics and
comparative test piece without defect characteristics;In the
comparative test piece is scanned by ultrasonic
phased array, and the standard echo parameter contrast table of
comparative test piece disassembly state is obtained;The comparative test piece is installed in the inside of gas tree
wellhead valve, and is scanned again by ultrasonic
phased array, and the standard echo parameter contrast table of comparative test piece is obtained under the condition of not disassembly;Make echo feature contrast chart;The
valve stem simulation test piece is installed in the inside of gas tree
wellhead valve, and is scanned by ultrasonic
phased array, and the structure characteristic waveform chart of valve stem
simulation test piece is obtained, and the structure characteristic waveform chart and the echo feature contrast chart are compared and analyzed.The application can realize that, without disassembly valve,
corrosion defect on the surface of valve stem in the inside of valve is realized online detection.