TBM Sealing Materials

Main Bearing Sealant — CTR-MBS-P

Clay-thickened lubricating grease for TBM main bearing lip-seal systems. Biodegradable, self-extinguishing, and pumpable.

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Main Bearing Sealant CTR-MBS-P
TBM Sealing Material · Pump-type

Main Bearing Sealant

Model CTR-MBS-P

Clay-thickened lubricating grease formulated specifically for the lips sealing system of TBM main bearings. Based on mineral oil and polymers, it contains solids, fibers and graphite to create an effective barrier against soil, water and dust ingress through the main bearing sealing system.

The product is delivered via the TBM's centralised pump system directly to the sealing lips. Its fiber structure maintains cohesion under wet, high-pressure conditions while remaining pumpable across the full range of site temperatures. Biodegradable and self-extinguishing — it meets EU environmental and fire safety requirements without hazardous classification.

At a Glance
AppearanceBlack fibrous paste
Density1.25±0.05 g/cm³
Penetration255±20 (1/10mm)
Flash Point≥220°C
Pumpability30–60 g/min
FlammabilitySelf-extinguishing
EcoBiodegradable
Specifications

Technical Data

PropertyValueTest Method
AppearanceBlack fibrous pasteVisual
Density1.25±0.05 g/cm³—
Penetration255±20 (1/10mm)—
Flash Point≥220°C—
4-Ball Grinding Test<0.9 mm (wear scar diameter)—
Pumpability30–60 g/minNF T60-139
FlammabilitySelf-extinguishing—
BaseMineral oil and polymers—
AdditivesSolids, fibers, graphite—
BiodegradabilityBiodegradable—
Hazard ClassificationNot classified as dangerous (EU CLP)EU CLP
Transport RegulationNot regulated—
Performance

Key Benefits

Excellent metal adhesion — maintains a tenacious film on sealing surfaces, preventing gap formation under dynamic loading and vibration.
High water resistance — fiber and solid content resists washout from groundwater infiltration and pressurised water ingress at the seal face.
Excellent pumpability — consistent flow at 30–60 g/min through centralised pump distribution systems across a wide temperature range.
Anti-washout with fiber cohesion — fiber structure maintains product integrity and prevents displacement even under continuous water exposure.
Self-extinguishing — automatically extinguishes when ignition source is removed, reducing fire risk in enclosed tunnel environments.
Biodegradable & safe — not classified as dangerous under EU CLP. Safe for groundwater and soil. Simplifies environmental compliance documentation.
Logistics

Packaging & Storage

Packaging Options
  • 25 kg drum
  • 70 kg drum
  • 230 kg drum
Storage & Shelf Life
  • Store at 10°C–35°C
  • Keep dry, away from direct sunlight
  • 12-month shelf life from manufacture date
  • Not classified as dangerous (EU CLP)
  • Not regulated for transport
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