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Spring-Energized PTFE Lip Seals for Cryogenic LNG Valves (-320°F)

Rubber seals turn into brittle glass at -40°F. But Liquefied Natural Gas (LNG) operates at -260°F (-162°C), and Liquid Nitrogen hits -320°F (-196°C). In these cryogenic zones, standard elastomers are useless.

Technical Specifications

  • Working Pressure Ratings: 1,000 PSI to 22,500 PSI (depending on union rating)
  • Durometer: 80-95 Shore A

Applications

  • Hydraulic Fracking: High-pressure sand and proppant injection lines.
  • Flowback Operations: Managing post-frac fluids and gases.
  • Choke & Kill Manifolds: Safety-critical well control connections.
  • Mud Lines: Circulating drilling mud systems.
  • Acidizing & Cementing: Handling abrasive cement slurries and acid fluids.

Spring-Energized PTFE Lip Seals for Cryogenic LNG Valves (-320°F)

1. Executive Summary: Sealing the Absolute Zero

Rubber seals turn into brittle glass at -40°F. But Liquefied Natural Gas (LNG) operates at -260°F (-162°C), and Liquid Nitrogen hits -320°F (-196°C). In these cryogenic zones, standard elastomers are useless.

Our Spring-Energized PTFE Lip Seals are the definitive solution for the Cryogenic sector. Combining a low-temperature PTFE Jacket with a corrosion-resistant Metal Spring Energizer, these seals maintain constant sealing force even when thermal contraction shrinks the hardware. They are the industry standard for BS 6364 Cryogenic Valve Testing.

2. Technical Innovation: The “Spring” Factor

Why a Spring?

PTFE has no “memory.” Once deformed or cooled, it doesn’t bounce back like rubber.

  • The Energizer: A high-performance metal spring (typically Elgiloy® or Stainless Steel 301) is inserted inside the U-shaped PTFE jacket.

  • Function: The spring provides a permanent elastic load. As the PTFE jacket shrinks in the cold, the spring pushes outward, maintaining positive contact with the sealing surface and preventing low-pressure gas leaks.

Cryogenic Jacket Material

We utilize specialized Modified PTFE or PCTFE (Kel-F) blends for the jacket. These materials retain mechanical toughness at cryogenic temperatures, resisting the cracking and flaking that can occur with inferior plastics.

3. Detailed Specifications

Technical Parameter Specification
Jacket Material Modified PTFE / PCTFE / TFM
Spring Material Elgiloy® (NACE Compliant) or SS 316
Temp Range -320°F to +450°F (-196°C to +232°C)
Spring Type V-Spring (Cantilever) or Helical Spring
Pressure Rating Vacuum to 6,000 PSI (ANSI Class 2500)
Friction Extremely Low (Stick-slip free)
Leakage Class Meets BS 6364 / ISO 28921

4. Target Applications: The LNG Chain

LNG Liquefaction & Transport

  • Loading Arms: Swivel joint seals for ship-to-shore transfer.

  • Cryogenic Ball Valves: Seat and stem seals that must operate at -162°C.

  • Submerged Pumps: In-tank pump seals for LNG storage vessels.

Industrial Gas

  • Liquid Nitrogen/Oxygen: Separation plants and cylinder filling stations.

5. Engineering Advantage

  • Unlimited Shelf Life: Unlike rubber O-rings which have a shelf life (e.g., 15 years), PTFE/Metal seals do not age. They can be stored indefinitely as spares.