Siemens offers two designs of high-speed electric motor driven hermetically sealed compressors. These types of compressors are particularly suited for remote unmanned operation and operators focused on minimal weight and space requirements, minimal system complexity, as well as low installation cost. Due to their absolute gas tightness they add to environmental compatibility and operational safety in hazardous environments or where particularly stringent environmental considerations play a major role. Hermetic sealing is achieved by placing the entire rotor system, including the motor, bearing system and compressor within a pressure containing enclosure requiring no shafts penetrations of the compressor casing. This eliminates the need for shaft seals and their associated auxiliary systems. By using active magnetic bearings there is no need for lubrication oil systems, eliminating the need for lube oil handling and spill prevention. The use of active magnetic bearings with advanced control algorithms, and the variable frequency drive system, enable unmatched flexibility in the speed ranges that can be achieved by these machines.