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Two-Ply Testable

METALLIC TWO-PLY TESTABLE EXPANSION JOINT

A safety-enhanced expansion joint featuring a two-ply bellows construction, allowing online monitoring and testing of bellows integrity for critical service applications.

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Two-Ply Testable

expansion joint

The Metallic Two-Ply Testable Expansion Joint is designed with two concentric bellows plies, creating an intermediate space that can be pressurized or evacuated to check for leaks. This enables in-service monitoring of the bellows’ condition, offering an additional level of safety in highly critical pipelines. The design is especially suited for hazardous media, high-risk environments, or systems that require absolute operational reliability.

  • Size Range (DN)

    DN50 – DN5000

  • Materials

    SS304 / SS316L / SS321 / Inconel / Hastelloy / others on request

  • Movements

    Axial (primary), with limited Lateral & Angular

  • Pressure Rating

    Up to 100 bar (higher on request)

  • Temperature Range

    –196°C to +800°C (depending on material)

Two-Ply Testable

expansion joint

The Metallic Two-Ply Testable Expansion Joint is designed with two concentric bellows plies, creating an intermediate space that can be pressurized or evacuated to check for leaks. This enables in-service monitoring of the bellows’ condition, offering an additional level of safety in highly critical pipelines. The design is especially suited for hazardous media, high-risk environments, or systems that require absolute operational reliability.

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  • Size Range (DN)

    DN50 – DN5000

  • Materials

    SS304 / SS316L / SS321 / Inconel / Hastelloy / others on request

  • Movements

    Axial (primary), with limited Lateral & Angular

  • Pressure Rating

    Up to 100 bar (higher on request)

  • Temperature Range

    –196°C to +800°C (depending on material)

Typical use case: Extensively applied in hazardous media pipelines (toxic gases, aggressive chemicals, or radioactive fluids) where continuous monitoring of bellows integrity is critical to safety.

Other applications include:

  • Oil & gas refineries and offshore facilities
  • Chemical and petrochemical plants
  • Nuclear and power generation plants
  • Cryogenic and high-purity process systems
  • Two-ply bellows design allows online monitoring of integrity
  • Early leak detection improves operational safety
  • Reduces downtime by enabling in-service condition testing
  • Excellent resistance to high temperature, pressure, and aggressive media
  • Enhances reliability in critical service applications
  • Long fatigue life through multilayer bellows construction
  • Flexible connection options: weld ends, fixed/loose flanges
  • Optional accessories include liners, covers, and monitoring ports
Pending
Test Port

for monitoring and leak detection between the two plies

Flow Liner / Inner Sleeve

protects against erosion from process media

End Connections

weld ends, fixed flanges, or loose flanges

External Covers / Shrouds

safeguard against mechanical damage

Limit Rods / Adjustment Rods

ensure controlled movement during operation