Screw Vacuum Pump: A rotary screw pump is probably the earliest developed positive displacement pumps which was known as the Archimedes‘ screw. In its most straightforward kind, this pump contains only one screw inside a hollow cylinder. Contemporary layouts integrate double or triple screws meshing in opposition to one another. https://bestschoolsinbhopalwithfe79013.suomiblog.com/the-ultimate-guide-to-vacuum-pump-42313647