Dry Running Agitator Mechanical Seal

Sealing the Vessel, Not Just the Shaft

An agitator seal has a different job than a pump seal from the outset — it's mounted on top of a reactor or vessel, sealing against a shaft that's often longer, less rigid, and subject to more runout from the mixing blades below than any pump shaft would see, which is why the dry running design leans on a non-contacting, gas-lubricated face rather than depending on the vessel's contents for lubrication. That distinction matters most in batch processes where the vessel runs empty between cycles, or under vacuum where liquid-lubricated faces would run dry and score regardless of design intent. Fitting one means securing the seal housing to the vessel's top flange, aligning the agitator shaft through the seal bore, and connecting the gas or air barrier supply before checking for shaft runout within tolerance — a step that matters more here than on a typical pump installation. For complete step-by-step installation instructions and torque specifications, refer to our detailed installation guide on the blog.