Para que servem as molas dentro dos retentores?

What are the springs inside the retainers for?

Spring seals provide durable and reliable sealing solutions in critical applications and extreme operating conditions across various industries.

This seal design extends the operational limits of polymer-based seals by:

  • Supply of gas-tight sealing systems to end users
  • Contribute to meeting fugitive emissions reduction objectives
  • Meet the requirements of environmental legislation

Spring-loaded seals are a highly reliable option when standard elastomer and polyurethane-based seals do not meet the operational limits, equipment parameters, or environmental conditions of your application. Even when a standard seal can meet basic needs, many engineers turn to spring-loaded seals for an added level of reliability and peace of mind.

Spring Seal Design

Basic design parameters of spring seals: Spring Seals - Project

  • Made from high-performance fluoroplastic compounds and engineering plastics that have exceptional physical and technical characteristics, but are rigid rather than flexible.
  • Use springs to provide a constant load around the entire circumference of the seal and create an airtight seal between the casing and hardware.
  • Use system pressure to create additional sealing strength between the casing and hardware.
  • In this combination, the spring pushes the sealing lips against the gasket and stem surfaces while the pressure helps the spring force.
  • The result: leak-free virtual sealing, high reliability and longer asset life.

When to use spring energized seals?

Exceptional physical and technical characteristics make spring seals the ideal choice in a wide variety of critical industrial equipment and applications.

Spring seals can be used in dynamic and static applications. Dynamic applications encompass reciprocating (linear), rotary and oscillating motion or any combination.

Spring seals - dynamic applications

Considerations when determining whether to use standard polymer seals or spring seals include:

  • Temperature (maximum/minimum possible operation and environment)
  • Operating pressure (which is not necessarily the maximum pressure in the system)
  • Speed ​​(movement speed)
  • Fluids (chemical compatibility: particularly important in the case of aggressive fluids)
  • Level of friction and wear
  • Environment (e.g. abrasive conditions)
  • Application and operation of the equipment
  • Sealing cavity configuration
  • Limitation of validity period

Where to use spring energized seals?

Spring seals are used in a wide variety of rotating, reciprocating, oscillating and stationary fluid production and materials processing equipment/systems.

Key industrial areas for use include:

  • Oil and Gas Industry (upstream and downstream)
  • Aerospace
  • Instrumentation Spring seals – For critical applications
  • Chemical processing
  • Energy sector
  • Doctor
  • Military
  • Transport
  • Automotive sector

Example: applications in the oil and gas industry

Focusing on the oil and gas industry, typical spring-loaded applications are:

  • Transfer systems:
    • Joints (connect/disconnect and disconnect)
    • Swivel joints
  • Submarine equipment:
    • Valves and manifolds
    • flow meters
    • Hydraulic joints
    • Bombs
  • Exploration:
    • Tools (drilling and downhole)
    • Wells (surface and underwater)
  • Floating production:
    • rotating tower
  • Offshore platforms:
    • Bombs
    • Compressors

Application Challenges Spring Seals - Industrial Applications :

  • Cryogenic temperature
  • Rapid gas decompression
  • High pressure and/or high temperature
  • Aggressive chemicals
  • Heavy environment
  • Low fugitive emissions

How do spring seals work?

Spring seals are typically made from high-performance fluoroplastic compounds and engineering plastics.

Typical material classes are:

  • PTFE (virgin and filled versions)
  • PEEK compound (unfilled and filled versions)

These materials have exceptional physical and technical characteristics, but they are not elastic. They are best characterized as rigid. Therefore, it is necessary to use different types of springs to mechanically energize the sealing lips. Thus the technical term “Spring Energized Seal” is reflected in the design/construction of the sealing device, where the spring compensates for polymeric materials with low memory/elasticity.

Spring seals: how they work

Retaining forces of a spring seal:

  1. When the seal is installed in the seal cavity, the seal lips and spring energizer are deformed/compressed in the radial direction.
  2. The spring energizes the liner, providing resiliency to the lips (pushing the sealing lips outward) and resulting in an effective sealing device in dynamic and static applications. This creates a gas-tight seal against counter surfaces.
  3. Additionally, radial tension (created and maintained by the spring in the sealing sleeve) keeps the sealing lips in contact with opposing surfaces (even before system pressure is applied, providing good sealing ability at low pressure)
  4. When system pressure is applied, the spring action is intensified. This increases the sealing force at the sealing lips, improving sealing efficiency. This is why the radial tension is always greater than the pressure to be sealed.

This tension can also compensate:

  • Moderate equipment deformation
  • Deflection eccentricity caused by possible misalignment
  • Manufacturing tolerances and clearances
  • Wear, thermal expansion and contraction.

The spring can also help compensate for wear on the dynamic sealing lips.

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