Slide valve for screw compressor

1. An assembly of a compressor for pressurizing a fluid comprising:

a main housing having a portion being substantially planar;

at least two parallel intersecting bores;

at least two rotors journaled for rotation within said bores;

a cover;

a plurality of vent channels in said main housing extending outwardly from at least one bore of the two parallel intersecting bores through said portion being substantially planar; the vent channels are configured for the fluid to flow through said vent channels;

a slide valve assembly operably connected to said housing proximate said plurality of vent channels, said slide valve assembly having a valve plate;

wherein said valve plate has a substantially planar side that is sealingly engaged with said planar portion of said main housing and rotatable relative to said planar portion of said main housing;

wherein said valve plate is positioned into one of a plurality positions relative to said vent channels, wherein said position in which said valve plate is positioned is are selected from a group comprising of: a fully open position, a fully closed position, and an intermediate position; and

wherein said valve plate comprises a side opposite said planar side, said side opposite bearing against said cover, said side opposite has a recess which does not bear against said cover, said cover delimiting a chamber, said chamber also delimited by a portion of said main housing.

2. The assembly of the compressor for pressurizing a fluid of claim 1 wherein said valve plate is variably rotatable from said closed position to said open position.