Heavy duty solutions for medium and high pressures operations are widely used on multistage and boiler feedwater pumps.
The BM3A has a type A pinned stationary seat, pressure balanced, manufactured in accordance with UNI EN 12756 (ex DIN 24960).
Both are suitable for clockwise or anti-clockwise rotation.

With the three drive lugs on the rotating body, they can tolerate high levels of vibration, and mechanical stress.
The O-ring is easily removed and refitted when assembling the seal on shafts with keyways, threads or sharp edges.
The BM3A is a multi-spring version more suitable for clean liquids.