LIQUID-FEEDING SCREW COMPRESSOR

A liquid-injected screw compressor includes: a casing that houses a screw rotor and a bearing, and has a suction port and a suction chamber connected to the suction port; a suction throttle valve that is installed at the suction port, and has a housing; and an intake-gas bypass system that establishes communication between a primary side and a secondary side of the suction throttle valve. The intake-gas bypass system includes: an intake-gas bypass flow path that is provided in a wall section of the housing, and has a primary-side opening section opening into the primary side of the suction throttle valve, and a secondary-side opening section opening into the secondary side of the suction throttle valve; and a first check valve arranged in the intake-gas bypass flow path. The intake-gas bypass flow path has an external opening section that opens to an outside of the housing and that allows insertion and withdrawal of the first check valve. Thereby, it is possible to make the system that communicates with the suction chamber in the casing and is provided with the reverse-flow inhibition mechanism a pipeless structure without impairing advantages of external pipes.