Abstract: In a sealing device (1) for sealing the through hole of an electrode, the pressurizing medium that generates the pressure of mechanical sealings against a rod electrode structure is an inert gas, such as nitrogen. The means for pressing the created sealing ring (6) against the rod electrode structure (4) include a gas distribution chamber (8) surrounding the sealing ring (6); a first channel (9) that is arranged to provide a flow path for the inert gas in between the hose (14) and the gas distribution chamber (8); an annular groove (10) in the sealing surface (7) of the sealing ring (6); and a second channel (11), which is placed in the sealing ring (6) and is arranged to provide a flow path for the gas from the gas distribution chamber to the groove (10) for extruding the gas in between the sealing surface (7) and the rod electrode structure (4).

Abstract: A stuffing box for a polished rod used with a downhole pump uses injectable packing to provide a seal around the polished rod. The stuffing box has a chamber for receiving the packing. The chamber has an opening to allow the addition of packing to the chamber. The packing is maintained in a compacted condition by either injecting additional packing through the opening or adjusting the volume of the chamber.