A tube mill labyrinth seal is usually made of cast iron. When the cast iron wears, the debris and grit produced gets into the roller bearing causing damage.

A further problem which occasionally occurs is side movement of the shaft.

Because the labyrinth seal is made of cast iron, breakage of the housing can occur, causing damage to the pillow block.

Three roller bearings are used on the Tube Mill, and are protected by labyrinth seals. The seals are greased.

• Lower cost
• No grit when cast iron shaft wears
• If the shaft shifts, it breaks the Vesconite seal and not the bearing housing. Vesconite acts as a mechanical fuse, limiting further expensive damage.