ST Guard
Proactive Stern Tube Care
ST Guard is a proactive stern tube treatment designed to help reduce friction, protect critical sealing surfaces, and support long-term seal performance. By forming a low-friction protective layer inside the system, ST Guard helps maintain stable operation and reduce wear over time.
System Compatibility & Blending
ST Guard is based on high-quality mineral stern tube oil and is designed to blend with most commonly used mineral stern tube lubricants.
Oil Compatibility Note
ST Guard is intended for selected mineral oil-based systems. For EAL or bio-oil systems, compatibility must be reviewed separately based on oil type, viscosity, additive package, system condition, and operating environment.
Suitable System Types
ST Guard can be considered for aft seal, forward seal, and stern tube applications, as well as common lip seal, face seal / Cedervall-type, air seal, and selected CPP-related sealing arrangements where applicable.
Assessment Before Application
Each application is reviewed individually to ensure the treatment is suitable for the system and operating conditions. This helps ensure correct blending, dosage, and onboard application guidance.
Application Example
Developed for real operating conditions across a wide range of vessel types and sealing systems.
ST Guard - Proactive Care for a Coastal Cargo Vessel
Vessel type: Coastal cargo vessel
Stern tube volume: ~800 L
Observed leakage: Within normal operating range
Scenario
The vessel was operating under stable conditions with no significant leakage. During longer runs, the crew observed elevated operating temperatures and wanted to reduce friction, protect sealing surfaces, and support long-term seal performance as part of routine maintenance.
Action
Based on the system volume and operating profile, a proactive treatment was recommended.
Recommended starting point: ST Guard
Indicative quantity: ~10 L total
Application
The product was applied during a scheduled port stay as part of planned maintenance.
Outcome
The system remained stable, with added support for friction control, surface protection, and long-term sealing reliability.
Request ST Guard
Send us your vessel details, and we'll help assess dosage, application, and compatibility.