Screw Vacuum Pump: A rotary screw pump is one of the earliest made favourable displacement pumps which was called the Archimedes‘ screw. In its most basic variety, this pump consists of just one screw within a hollow cylinder. Present day layouts include double or triple screws meshing against each other. https://admissionbhopalschool50503.bluxeblog.com/58790012/the-definitive-guide-to-air-compressors