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From Seal Failure to Production Hero: A Cryogenic Case Study

 

Introduction

Cryogenic systems present some of the most demanding challenges in sealing technology. Whether it’s liquid nitrogen (LN2), LNG, or other cryogenic gases, temperatures plunging to -196°C or below can cause traditional elastomer seals to crack, shrink, or leak. This case study explores how a critical sealing failure in an LNG valve was transformed into a performance breakthrough—thanks to a custom-engineered PTFE spring-energized seal from Parjet.

 

The Problem: Persistent Leakage in LNG Valves

A global gas distribution company operating an LNG refueling station reported recurring leakage issues in their cryogenic shut-off valves. The leakage, though minor at first, grew with each thermal cycle, eventually causing unexpected downtime during peak distribution hours. Their original seal—a standard elastomer-based O-ring—was unable to maintain elasticity under cryogenic contraction and showed signs of brittleness and leakage within weeks.

 

The Consequences

• X Loss of pressure control during LNG transfer
• X Frequent maintenance and valve replacement
• X Safety concerns due to vaporized gas emissions
• X Operational downtime and client dissatisfaction

The client knew they needed more than just another O-ring—they needed a long-term solution.

 

The Solution: Spring-Energized PTFE Seal by Parjet

Our engineering team at Parjet performed a root cause analysis and quickly identified material brittleness and poor dimensional recovery as the main issues. We proposed a HiPerSeal® spring-energized seal using:

•  - A PTFE-based jacket filled with glass fiber for added dimensional stability
•  - A helical spring energizer, chosen for its ability to maintain radial sealing force at sub-zero temperatures
• - Geometry optimized via FEA simulation to ensure performance under thermal contraction and dynamic movement

The seal was custom-fit into the valve gland with minimal design changes, allowing for a smooth upgrade without retooling.

 

The Result: From Downtime to Hero

After replacing the legacy seals with Parjet’s PTFE spring seals, the system underwent:

• - 12 consecutive months of leak-free operation
• - Reduced maintenance frequency by over 60%
• - Enhanced safety performance in cryogenic transfer
• - Improved thermal cycling tolerance

The LNG refueling station not only resolved their leakage issues but also reported higher operational confidence, even during peak cold flow operations.

 

Why Spring-Energized PTFE Seals Work for Cryogenics?

• - Compensation for Shrinkage: Spring force maintains contact even as materials contract
• - Non-brittle Material: PTFE retains flexibility far below freezing
• - Chemical Resistance: Ideal for LNG and nitrogen exposure
• - Low Friction: Enables dynamic motion in valves and pumps

 

Industries That Benefit

• - Aerospace (liquid oxygen/hydrogen systems)
• - Pharmaceutical cryo storage
• - Oil & Gas
• - Scientific & semiconductor labs

 

Introducing Parjet’s HiPerSeal^®

Parjet is a vertically integrated sealing solution provider with over 30 years of experience. Our in-house capabilities—from raw PTFE powder to CNC-machined seals—ensure material consistency, tight tolerances, and rapid customization. We specialize in spring-energized seals (HiPerSeal^®) including cantilever springs, helical springs, and canted coil springs for extreme applications like cryogenics.

 

Conclusion

This case proves that the right sealing technology can transform an operational weakness into a production advantage. If your cryogenic systems are struggling with brittle seals or leaks, it’s time to consider a smarter solution—spring-energized PTFE seals from Parjet.

Feel free to contact us to request a custom cryogenic sealing consultation or seal sample.