Abstract: A dry vacuum pump has a stator (2) and two rotors (5) that are accommodated in at least one compression chamber (3) of the stator (2), the rotors (5) being configured to rotate synchronously in opposite directions so as to drive a gas to be pumped between an intake and a delivery of the vacuum pump. The rotors (5) and the compression chamber (3) of the stator (2) are coated with a nickel-phosphorus coating (11) comprising between 9% and 14% phosphorus and having a thickness greater than 20 ?m, the nickel-phosphorus coating (11) having undergone a hardening heat treatment comprising a step of heating to a treatment temperature greater than 250° C. for a treatment duration greater than one hour, so as to have a hardness greater than 700 HV.

Abstract: A gas treatment device treats, at atmospheric pressure, the gases pumped by at least one rough pumping device. The gas treatment device includes a treatment chamber and at least one discharge pipe to connect a discharge of the at least one rough pumping device to an inlet of the treatment chamber. The gas treatment device further includes at least one auxiliary pumping device to lower the pressure in the at least one discharge pipe, situated less than 1 meter from the inlet of the treatment chamber, such as less than 50 cm.