Stainless Steel Metal Bellows Expansion Joint for Plumbing

Plumbing Items Metal Corrugated Welded Stainless Steel Flexible Metal Expans Bellow

Product Description:

Bellows expansion joints (metal bellows expansion joints) are flexible connection devices used to absorb displacement and deformation of piping systems caused by thermal expansion and contraction, vibration or foundation settlement.

Main structure:
Metal bellows: core component, usually made of stainless steel (such as 304, 316L), providing flexibility through multi-layer or single-layer corrugated structure.

Flange/welding end: connected to the pipeline, flange type is easy to disassemble, and welding type has better sealing.

Limiting pull rod/hinge: prevent excessive compression or stretching, protect the bellows.

Outer sheath (optional): dustproof and mechanical damage proof.

Common types:

Core parameters and selection points

• Compensation

Axial compensation: the maximum displacement that the bellows can compress/stretch (such as ±50mm).

Lateral compensation: depends on the length and structure of the bellows.

• Pressure level

Need to match the pipeline working pressure (such as 0.6MPa, 1.6MPa, 2.5MPa).

• Temperature range

Conventional material (304 stainless steel): -196℃~+450℃; high temperature requires special materials (such as Inconel).

• Fatigue life

Usually ≥1000 cycles (need to be checked according to the displacement).

• Connection method

Flange type: ANSI, DIN, GB standard flange.

Welded type: suitable for scenes with high pressure or high sealing requirements.

Common Problems and Solutions

Bellows leaks:

Cause: corrosion/fatigue cracking
Solution: Replace with higher quality material (such as 316L), add anti-corrosion layer

Insufficient compensation:
Reason: wrong selection or excessive pipe displacement
Solution: recalculate displacement and replace with a larger compensation model