Externally Pressurized Expansion Joints
Externally pressurized expansion joints are built for applications with high axial movement and high pressure. The bellows are arranged so process media flows on the external side, while the inside stays at atmospheric pressure. This eliminates column instability as a design limitation, since external pressure has a stabilizing effect on the bellows rather than causing buckling, allowing large axial compensation with a protective outer cover.
Description
Specifications
- Bellows material: 304, 316, 321 stainless steel
- Balance of material: Carbon steel, stainless steel
- Design pressure: Up to 40 barg
- Design temperature: Up to 400°C
- Size range: DN25 to DN250 (flanged or weld end)
Advantages
- Used where large axial movements are required
- Eliminates column instability concerns for the bellows
- Outside cover protects bellows from external elements
- Inner pipe liner streamlines flow and minimizes pressure losses
Applications
- Hot and cold water pipelines, superheated water
- Steam and condensate pipelines
- HVAC lines, geothermal plants
- Underground pipelines and city district heating
