marine water lubrication stern shaft (stern tube) sealing apparatus is suitable for kinds of ships, which are with water lubrication stern tube bearing. There is pneumatic seal, so that it can be inspected, adjusted, and maintained without docking. It suit for following shafting technical specifications Shaft dia.: 50mm to 800mm Shaft bush dia.: 70mm to 850mm Axis speed: less than 7m/s Lubrication water working pressure: less than 0.2MPa Pneumatic inflation pressure: 0.2MPa to 0.6MPa Average leakage rate: less than 300ml/h Axial movement: < ±0.5