In addition to selling vacuum pump rebuilds, PTB Sales can provide refurbished blowers and pump/blower packages.
Blowers (Rotary lobe blowers, Roots style, vacuum boosters, etc...) are used to boost the pumping speed and reduce back streaming of oil of most rough pumps. A vacuum blower requires a backing pump that has a rating of at least 10 percent its pumping speed.
Rotary lobe pumps have two counter rotating lobes which essentially "dove tail" or mesh without touching. These lobes continuously transfer gas from the inlet to the exhaust at a rate of 50 cfm to 100,000 cfm at a pressure of .1 to 10 Torr. There is a certain clearance that must be gauged during refurbishing, between the rotors and between each rotor and the stator wall. This clearance allows the pump to operate without mechanical wear and without the need for lubrication inside the swept volume.