Screw compressor

A screw compressor, comprising:

• a casing having a low-pressure space and a high-pressure space formed therein;
• a screw rotor having a plurality of helical grooves forming a compression chamber, the screw rotor being configured to be inserted in a cylinder part of the casing;
• and
• a slide valve disposed in the cylinder part, the slide valve being moveable along an axis of the screw rotor and facing an outer periphery of the screw rotor to form a discharge port communicating the compression chamber with the high-pressure space,
• a fluid in the low-pressure space being sucked into the compression chamber, compressed, and then discharged to the high-pressure space when the screw rotor rotates, and
• the slide valve including a sealing projection
• located on a back surface of the slide valve opposite to the screw rotor and
• separating the low-pressure space and the high-pressure space from each other when the sealing projection is in slidable contact with the casing.