Abstract: This paper summarizes and analyzes the trip-out of rich gas compressor turbine in delayed coking unit when it reaches a certain load in the production process under the condition of good single-unit test run and unit linkage test run after maintenance. The results indicate that the final reason is that the back cap of the one-sided stay bolt is loose and the front bearing seat expands unevenly; then the pull hook of the emergency safety device makes radial contact with the head of the flying hammer of the emergency governor. These lead to quick shut-off oil and pressure relief and closing of the quick closing valve, which results in the trip-out of the steam turbine. By taking effective measures, the sudden trip-out of the unit is eliminated and this ensures the safe and stable operation of the unit.

Key words: steam turbine, stay bolt, emergency safety device, emergency governor