The physical properties of any material varies with temperature. Limits for operating temperature are affected by the working pressure, the type of media being conveyed and the nature of the application. By careful selection of material, it is possible to provide an expansion joint for a wide range of operating temperatures. The choice of type, metal alloy, end fitting and method of fitting attachment determines the temperature limit.
Why are Metal Expansion Joints Important?
Where piping designs are subject to changes in temperature, pressure, vibration, compression extension, cyclical movements or movements required in usage, flexible metal hose and metal expansion joints, in tandem or alone, are needed to preserve the integrity of your system.
Factors Determining the Selection of Bellows
Untied Expansion Joints
Tied Expansion Joints
- Axial Expansion Joints — Singular or dual bellows with installation fittings only
- Double Expansion Joint — Commonly used for low-pressure service
- Internally Guided Expansion Joint — Simple design = less expensive
- Untied Universal Expansion Joints — All degrees of freedom (axial, lateral, angular)
- Pressure Balanced Expansion Joint — Anchors affected by bellows spring rate and pressure thrust = higher force
- Hinged Expansion Joints — Single or dual bellows with restraining hardware
- In-line Pressure Balance Expansion Joint — Typically used for high-pressure service
- Gimballed Expansion Joints — Limited degrees of freedom
- Tied Single & Universal Expansion Joints — Anchors only affected by bellows spring rate = low force