Vacuum air pump is used in power plant,vacuum metallurgy, welding, chemistry, pharmacy, coating and ... Vacuum Insulation Oil Recycle MachineVacuum Pumping UnitVacuum air pump fast in startup and pumping, and thus is especially suitable for ... of transformers.Besides, it can also be used for vacuumization in vacuum metallurgy, welding, chemistry, pharmacy, coating and electronic industries... ...