All of the replacement high vacuum pumps from Vaccum Pumps UK may run continuously connected to closed containers to be emptied, and may not run continuously at length, at atmospheric pressure. The exhaust from these pumps is not filtered, thus, special purifiers are available for fumes. The operating principle of the replacement high vacuum pumps is like the lubricated rotary vane vacuum pumps. However, in this case, the stator is immersed in the lubrification oil which has also the function of sealing the air loss. The pressure levels reached by this type of pump are higher than any other rotary vane pump. These pumps are equipped with a gas ballast system to avoid the condensation of the water vapour.