Full definition
Pre-assembled mechanical seal in a sleeve that includes all components—faces, springs, secondary O-rings—in a sealed, pre-set unit. Installs as a complete assembly with no field measurements or adjustments, eliminating 80% of assembly errors. Reduces maintenance time by 50-70%. Available for shaft diameters 20-120 mm. Leading manufacturers: John Crane, EagleBurgmann, Flowserve.