Abstract: An improved purge gas supply that is less susceptible to the shortcomings of known systems. The disclosure aims to reduce backflow or recirculation of pumped gases into the purge supply apparatus by providing an arrangement where the purge ports on a multistage vacuum pump contains purge gas at sufficient pressure to resist the backflow, particularly when the vacuum pump is operating outside of its ultimate pressure regime. Embodiments of the purge supply apparatus described herein do not necessarily need a non-return valve to resist the unwanted pump gas back-flow.

Abstract: An improved purge gas supply that is less susceptible to the shortcomings of known systems. The disclosure aims to reduce backflow or recirculation of pumped gases into the purge supply apparatus by providing an arrangement where the purge ports on a multistage vacuum pump contains purge gas at sufficient pressure to resist the backflow, particularly when the vacuum pump is operating outside of its ultimate pressure regime. Embodiments of the purge supply apparatus described herein do not necessarily need a non-return valve to resist the unwanted pump gas back-flow.

Abstract: A pump comprises a rotor arrangement and a stator arrangement. The stator arrangement comprises a first part made from a corrosive resistant material which defines a volume which in use is swept by the rotor arrangement for pumping fluid from an inlet to an outlet of the stator arrangement. A second part of the stator arrangement is made from a thermally conductive material which envelopes the first part so that heat generated in the first part can be transferred to the second part at the interface surface between the two parts. The second part has formed therein at least one duct for conveying a liquid coolant through the second part so that heat can be transferred from the second part to the liquid coolant for cooling the stator arrangement.

Abstract: A pump comprises a rotor arrangement and a stator arrangement. The stator arrangement comprises a first part made from a corrosive resistant material which defines a volume which in use is swept by the rotor arrangement for pumping fluid from an inlet to an outlet of the stator arrangement. A second part of the stator arrangement is made from a thermally conductive material which envelopes the first part so that heat generated in the first part can be transferred to the second part at the interface surface between the two parts. The second part has formed therein at least one duct 80 for conveying a liquid coolant through the second part so that heat can be transferred from the second part to the liquid coolant for cooling the stator arrangement.

Abstract: A method for managing deposits within a pump mechanism (81) is provided. Fluid suitable for dissolving, diluting or otherwise disengaging deposits which have accumulated on the internal working surfaces of the pump is brought into contact with the mechanism. The performance of the pump is monitored and this data is used together with process data received from, or associated with, a tool (83) being evacuated by the pump to calculate (80) fluid flow characteristics which are required to compensate for the accumulation of deposits on the internal working surfaces of the pump. Fluid is then introduced (2, 84) into the pumping mechanism in accordance with the calculated fluid flow characteristics.

Abstract: A system (100) for supplying an inert purge gas to a pumping arrangement (106) includes a plurality of flexible capillary tubes (102) each for conveying the gas from a respective outlet of a manifold (12) to a respective port (104) of the pumping arrangement (106). The internal diameter and length of each tube (102) control the gas flow rate to the respective port (104).

Abstract: A system (100) for supplying an inert purge gas to a pumping arrangement (106) includes a plurality of flexible capillary tubes (102) each for conveying the gas from a respective outlet of a manifold (12) to a respective port (104) of the pumping arrangement (106). The internal diameter and length of each tube (102) control the gas flow rate to the respective port (104).