Disclosed is a pumping system with reduced contamination. A vacuum pump system includes a mechanical vacuum pump mechanism within a hermetic pump that hermetically isolates the pump mechanism from ambient air. A pump inlet is hermetically sealed to the hermetic pump housing. A pump outlet is hermetically sealed at one end to the hermetic pump housing and at the other end to an inlet of a Peclet seal tube. The vacuum pump system produces a vacuum in a vacuum processing chamber. A sweep gas source injects a sweep gas into at least one of (i) the hermetic pump housing and (ii) the inlet of the Peclet seal tube. The sweep gas and a process gas flow through the Peclet seal tube to substantially isolate against the backflow of the ambient air through the Peclet seal tube.

A furnace for thermal treatment with gaseous atmosphere quenching having a bell inside which there are provided a rotor regulating the gas atmosphere flow, a heat exchanger regulating the temperature of the gas atmosphere and a thermal chamber configured for thermal treatment and the following gaseous atmosphere quenching. The thermal chamber has at least a surface positioned on a side adjacent to the heat exchanger and at least a surface positioned on an opposed side to the adjacent one to the heat exchanger and wherein at least a surface has a plurality of screens which connect the inside of the thermal chamber with the inside of the bell to allow the passage of the gas atmosphere from the thermal chamber to the bell, wherein the screens are adjustable to modify the passage section and so the flow of the gas atmosphere in function of the temperature required by the thermal treatment.