Screw Vacuum Pump: A rotary screw pump is probably the earliest designed optimistic displacement pumps which was often called the Archimedes‘ screw. In its most straightforward form, this pump includes a single screw inside of a hollow cylinder. Present day designs include double or triple screws meshing towards each other. https://myinlasertrngenhp87531.digitollblog.com/26668942/little-known-facts-about-air-compressors