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:
| Type | Features | Application Scenario |
| Axial type | Absorption pipe axial expansion and contraction (compression/tension) | Thermal compensation of straight pipe sections |
| Horizontal type | Compensation for lateral displacement perpendicular to the pipe axis | Pipeline lateral deviation or settlement |
| Angle type | Absorption duct angle variation (typically ±15°) | Angular displacement near the elbow |
| Universal hinge type | Multi-directional compensation (axial + lateral + angular) | Complex 3D piping system |
| Pressure Balance Type | Eliminate internal pressure thrust and protect fixed bracket | High-pressure, long-distance pipelines (such as steam pipe networks) |
Core parameters and selection points
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.
Need to match the pipeline working pressure (such as 0.6MPa, 1.6MPa, 2.5MPa).
Conventional material (304 stainless steel): -196℃~+450℃; high temperature requires special materials (such as Inconel).
Usually ≥1000 cycles (need to be checked according to the displacement).
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
Abnormal support force:
Reason: guide support or fixed support is not set
Solution: check whether the support layout meets the design requirements
If you encounter the above problems when using bellows compensators in pipelines, please contact us to provide you with professional technical guidance to ensure the safe and stable operation of the pipeline.
