Method of removing and reinstalling bottom entering agitator seals

In a method of removing and reinstalling a seal unit from a process vessel bottom entering agitator assembly wherein the assembly includes an agitator positioned within the vessel, an agitator shaft connected to the agitator having a connector at the bottom end thereof adapted to be connected to a support collar which is in turn adapted to be connected to the vessel, a seal unit having upper and lower seal unit shafts, the upper seal unit shaft being connected to the connector at the bottom end of the agitator shaft within the vessel and extending through a flanged opening in the vessel, the seal unit being positioned outside the vessel and connected to the flanged opening in the vessel and a coupling shaft connected to the bottom end of the lower seal unit shaft and to a rotary drive means, wherein the seal unit is removed by removing the coupling shaft from the assembly, disconnecting the seal unit from the flanged opening of the vessel, lowering the seal unit, agitator shaft and agitator connected thereto whereby the connection between the upper seal unit shaft and the agitator shaft is moved to a position outside the vessel, connecting the support collar to the connector at the bottom end of the agitator shaft, raising the seal unit, agitator shaft and agitator whereby the support collar is positioned adjacent the vessel, connecting the support collar to the vessel and then disconnecting the upper seal unit shaft from the agitator shaft whereby the seal unit is removed from the assembly and wherein the seal unit is reinstalled by carrying out the above steps in reverse order, the improvement which comprises:

• connecting a jack to the bottom end of said lower seal unit shaft and to the rotary drive means after removing said coupling shaft from said assembly;
• using said jack to lower and raise said seal unit, agitator shaft and agitator during the removal and reinstallation of said seal unit;
• disconnecting said jack from said assembly;
• and then
• reinstalling said coupling shaft in said assembly.