language

Blog

Latest industry updates are available here.

Company News

Industry News

Company News

Industry News

Back to Overview

Material Selection and Design Considerations for Metal Bellows Expansion Joints

Jan 23,2026

Specifying the correct Metal Bellow Expansion Joint requires a deep understanding of the operating environment and engineering principles. The first consideration is the bellows material. Austenitic stainless steels (304, 316L) are common for their formability and corrosion resistance. For high-temperature applications, alloys like Inconel 625 or 800H are used. The thickness, number of plies, and convolution geometry (U-shaped, Ω-shaped) are meticulously calculated to withstand the system's design pressure while achieving the required movement capacity.
Movement is quantified in three axes: axial, lateral, and angular. The joint must be sized to absorb all anticipated movements from thermal growth, equipment vibration, and anticipated misalignment without exceeding its rated cycle life—the number of flexing movements it can endure before fatigue. Pressure thrust, the force generated by internal pressure trying to extend the bellows, must be restrained by main anchors or through the use of tied, hinged, or gimbal joint designs that incorporate hardware to withstand this force.
Other design elements include internal liners to smooth flow and protect bellows from erosion, external covers for mechanical protection, and limit rods for safety. Engineers must provide accurate data on temperature, pressure, media, and calculated movements to ensure a reliable, durable, and safe expansion joint design that integrates seamlessly into the piping stress analysis.

The Advantages of Rubber Expansion Joints in Water and Wastewater Systems

Installation and Maintenance Best Practices for Dismantling Joints