STEAM TURBINE, PARTITION MEMBER, AND METHOD FOR OPERATING STEAM TURBINE

There is provided a steam turbine that has a configuration in which a pressure regulation valve is disposed in a region including outer peripheral side relative to a partition section and makes it possible to achieve downsizing. A steam turbine 1 includes a partition plate 10 that partitions a high-pressure stage 101 and a low-pressure stage 102, and a pressure regulation valve 30 configured to regulate pressure of extraction steam or pressure of steam to be mixed. The pressure regulation valve 30 includes a plurality of flow rate regulation valves V1 to V5 that are located on outer peripheral side relative to the partition plate 10 and to which steam is guided from the high-pressure stage 101 side relative to the partition plate 10, and a plurality of flow path compartment 31 to 35 that respectively correspond to the plurality of flow rate regulation valves V1 to V5 and communicate with the low-pressure stage 102 side relative to the partition plate 10. The plurality of flow path compartments 31 to 35 are arranged over the entire partition plate 10 in a circumferential direction in a region including the outer peripheral side relative to the partition plate 10 as a whole. The partition plate 10 includes a bypass passage 18 that makes the high-pressure stage 101 side and the low-pressure stage 102 side communicate with each other without passing through the pressure regulation valve 30.