In critical industrial applications—ranging from aerospace to petrochemical and high-pressure hydraulic systems—sealing reliability is non-negotiable. Among the most trusted solutions in these demanding environments is the PTFE spring-energized seal, commonly referred to as a Variseal or back-up lip seal.

A key feature that sets these seals apart is their multi-lip design. At DXTSEALS, we engineer and customize these seals to deliver unmatched reliability in high-stakes scenarios.

🔍 What Is a Multi-Lip Seal Design?

A multi-lip seal features two or more sealing lips strategically designed to:

• Distribute contact force evenly

• Provide redundant sealing layers (a backup in case of primary lip wear)

• Handle different types of dynamic movement (e.g., axial, radial, oscillating)

Combined with a spring-energized PTFE body, this architecture ensures consistent sealing even under:

• High pressures (up to 60 MPa)

• Wide temperature ranges (-60°C to 260°C)

• Chemically aggressive environments

⚙️ How Multi-Lip Designs Improve Sealing Performance

1. Redundant Sealing Layers for Fail-Safe Operation

When a single-lip seal wears out, the entire system risks failure. Multi-lip seals include secondary (and sometimes tertiary) lips that act as backups, maintaining sealing even if the first lip is compromised.

2. Better Load Distribution

Each lip shares the sealing force, which:

• Reduces overall wear rate

• Extends service life

• Minimizes deformation under high pressure

This is particularly useful in pulsating pressure systems, such as those in hydraulic cylinders and oil & gas valves.

3. Enhanced Contaminant Exclusion

The extra lips can function as dust or fluid exclusion barriers, blocking:

• Particles

• Water

• Chemicals
  …before they ever reach the primary sealing surface.

This is vital in dirty or abrasive operating environments like mining, marine, and heavy machinery.

🔬 Material Synergy: PTFE + Spring System

DXTSEALS multi-lip seals combine:

• High-purity PTFE or filled PTFE (e.g., PTFE + bronze, PTFE + glass)

• Stainless steel or Inconel® spring energizers (U-spring, V-spring, or helical)

This combination ensures:

• Low friction

• Excellent wear resistance

• Long-term resilience in dynamic applications

🏭 Applications That Demand Multi-Lip Seals

Multi-lip spring-energized seals are used across industries such as: