Dry screw vacuum pumps operate on a simple yet highly efficient principle where two intermeshing screw rotors rotate in opposite directions inside a housing, trapping air or gas and moving it from the suction side to the exhaust without the need for lubrication in the compression chamber. Because there is no contact between the screws and no oil or liquid in the pumping chamber, these... https://www.economysolutions.in/blog/understanding-the-principles-and-operation-of-dry-screw-vacuum-pumps-for-beginners