Triple Lip Rotary Seals

Triple lip rotary seals incorporate three distinct sealing lips to provide superior protection against both lubricant leakage and the ingress of aggressive external contaminants like sand, dust, water, and slurry. This design makes them a robust solution for demanding industrial environments.
Design and Function
The core advantage of a triple lip seal is its multi-stage sealing system, which provides redundancy and enhanced performance in harsh conditions.
Primary (Inner) Lip: The innermost lip forms the main barrier against the internal medium (oil, grease, etc.), ensuring it stays within the system.
Secondary Lip: This middle lip acts as a back-up for the primary seal, capturing any fluid that might bypass the first lip and contributing to overall containment.
Tertiary (Exclusion) Lip: The outermost lip faces the environment and functions as a heavy-duty dust wiper, actively blocking external debris from entering the seal area and internal components.
Enhanced Reliability: This layered approach means that even if one lip is compromised, the others continue to provide a substantial degree of protection, significantly extending the service life of the components it is designed to protect.
Materials
Material selection is critical for performance in extreme conditions and the lips are available in various elastomers and polymers.
Nitrile Rubber (NBR): A common, cost-effective option for general use with mineral oils and greases.
Fluoroelastomer (FKM/Viton): Offers superior heat and chemical resistance compared to NBR, making it suitable for more aggressive environments.
Polytetrafluoroethylene (PTFE): Known for its extremely low friction, high chemical inertness, and ability to handle high temperatures and speeds, including dry-running applications. PTFE variants often incorporate fillers like glass or carbon to enhance mechanical strength and wear resistance.
Casing Materials: Metal casings for structural integrity are typically made from standard or stainless steel to resist corrosion.