AST Advanced Sealing AST-50 Mechanical Seal Rotary Unit

The AST Advanced Sealing AST-50 Rotary Unit is a single outside mechanical seal designed to slide over the shaft and seal in corrosive or low-pressure service without any metal parts in direct contact with the pumped liquid. The 1-3/8" bore matches common shaft sizes, and the unit is intended for ANSI pumps and many other configurations, including Fybroc and Flowserve GRP non-metallic pumps. This externally mounted, hydraulically balanced seal uses a preset, multi-spring arrangement with springs isolated from the fluid, eliminating the need for sleeves, steps in the shaft, or pump modifications. Installation is quick and simple: slide the rotary unit over the shaft until it contacts the stationary face, tighten the drive ring, and remove the retaining clips. The AST-50 is positioned as a low-cost replacement for exotic-metal seals and is suitable for applications where outside sealing is preferred or required, including food processing environments where sanitation and cleanability are important.