1. Structure and Materials

Main Structure:

Bellows: 304/316L stainless steel (thickness 0.4-0.6mm) with U-type or Ω-type corrugations, enhancing axial/lateral compensation capability.

Flanges/Nozzles: Q235 carbon steel or stainless steel (304/316), compatible with DN200 pipeline standards (e.g., GB/T 9119-2010 or ANSI B16.5).

Flow Guide: Built-in stainless steel deflector to reduce medium erosion on the bellows (suitable for high-velocity fluids or particle-containing media).

Special Types:

Multi-layer Bellows: Improves pressure resistance (up to 4.0MPa) for high-pressure steam pipelines.

Outer Sheath: Carbon steel or insulation layer for low-temperature (≤-40℃) or high-temperature (≥400℃) working conditions.

2. Technical Parameters

Nominal Diameter: DN200 (corresponding to pipe outer diameter 219mm).

Working Pressure:

Standard type: 1.0MPa, 1.6MPa;

High-pressure type: 2.5MPa, 4.0MPa (custom multi-layer corrugations required).

Temperature Range:

304 stainless steel: -20℃~400℃;

316L stainless steel: -196℃~600℃ (suitable for low-temperature liquid nitrogen or high-temperature flue gas).

Displacement Compensation:

Axial extension: ≤25mm; axial compression: ≤35mm;

Lateral displacement: ≤30mm; angular deflection: ≤10°/m.

3. Product Features

Multi-directional Compensation: Absorbs axial, lateral, and angular displacements simultaneously, resolving pipeline stress caused by thermal expansion, foundation settlement, or equipment vibration.

Reliable Sealing: Bellows and flanges are welded using TIG (argon arc welding) with a leakage rate ≤1×10⁻⁶Pa·m³/s, meeting industrial pipeline sealing standards.

Fatigue Resistance: Withstands 10,000 cycles of displacement testing (±20mm axial displacement) without cracks or leaks, ensuring a service life of over 10 years (in indoor dry environments).

Flexible Installation: Weighs only 60% of flange-type expansion joints of the same 规格，reducing pipeline support loads and lowering installation costs.

4. Application Scenarios

Industrial Pipelines:

Chemical industry: Acid-alkali solution pipelines (316L for corrosion resistance);

Power industry: Boiler steam pipelines, cooling tower circulation pipes;

Metallurgy: Cooling water pipelines in steelmaking workshops (resistant to high-temperature impact).

Municipal Engineering:

Central heating networks (high-temperature water/steam);

Aeration pipelines in wastewater treatment plants (resistant to sewage corrosion).

Construction Sector:

Air conditioning water circulation systems in high-rise buildings;

Fire-fighting pipelines (compatible with 1.6MPa pressure class).

5. Installation and Maintenance Notes

Installation Requirements:

Ensure coaxial alignment of pipes and expansion joints (deviation ≤3mm) to avoid uneven stress on the bellows due to eccentric loads.

Reserve sufficient expansion space (≥1.2 times the designed compensation) for axial compensation.

Pre-stretch at room temperature (50% of total compensation) for high-temperature pipeline installation.

Maintenance Tips:

Regularly inspect for corrosion, deformation, or welding leaks (recommended every 6 months).

Clean foreign matter (sediment, welding slag) accumulated between corrugations to prevent local wear.

Gradually pressurize to working pressure before restarting after long-term shutdown to avoid pressure shocks.

6. Compliance Standards

China: GB/T 12777-2019 General Technical Conditions for Metallic Bellows Expansion Joints

International: ISO 14930:2009 Metallic bellows expansion joints for piping systems

Note: For specific media (e.g., chloride-containing fluids, high-temperature flue gas), custom materials such as Monel or Hastelloy can be used. Confirm details with the technical team.