All kinds of vacuum pumps work pressure range

reciprocating vacuum pump

1×10⁵～1.3×10² 

rotary-vane vacuum pump

1×10⁵～6.7×10^-1 

liquid-ring vacuum pump

1×10⁵～2.7×10³ 

Roots-type vacuum pump

1.3×10³～1.3

steam ejector pump

1×10⁵～1.3×10^-1 

oil diffusion pump

1.3×10^-2～1.3×10^-7 

titanium sublimation pump

1.3×10^-2～1.3×10^-9