Double hinged expansion joints, also known as dual hinged or two hinged expansion joints, are specialized components used in piping systems to accommodate angular movement in two planes. Here’s an overview of double hinged expansion joints:

1. Purpose: Double hinged expansion joints are designed to absorb angular movement or rotation in two perpendicular planes while maintaining the integrity and alignment of the piping system. They provide flexibility and allow for movement in multiple directions, typically in both horizontal and vertical planes.

2. Construction: These expansion joints consist of a bellows element connected to the adjacent piping sections by dual hinge hardware. The bellows, made of metal (such as stainless steel), are corrugated tubes designed to flex and accommodate angular movement. The dual hinge hardware allows the bellows to pivot and rotate independently in two perpendicular planes.

3. Flexibility: Double hinged expansion joints offer flexibility in two perpendicular planes, allowing for angular movement or rotation in both horizontal and vertical directions between connected piping sections. The bellows elements can pivot around the dual hinge points to absorb angular displacement while maintaining the alignment and integrity of the piping system.

4. Compensation for Angular Movement: Double hinged expansion joints are specifically designed to compensate for angular movement or rotation in two perpendicular planes between connected piping sections. This movement may result from thermal expansion, settlement of supporting structures, ground movement, or other dynamic forces acting on the piping system.

5. Application: Double hinged expansion joints are commonly used in piping systems where angular movement occurs in two perpendicular planes, such as pipelines connected to equipment with complex motion or in systems subjected to multi-directional thermal expansion or contraction.

6. Installation and Maintenance: Proper installation and maintenance are essential for the reliable performance of double hinged expansion joints. Installation should follow manufacturer guidelines, including proper alignment and support of the expansion joint. Regular inspection and maintenance help identify potential issues such as leaks, fatigue, or corrosion, allowing for timely repairs or replacements.

Double hinged expansion joints provide an effective solution for accommodating angular movement in two perpendicular planes between connected piping sections while maintaining system integrity and alignment. Proper selection and installation of these expansion joints are crucial to ensure the efficient operation and longevity of the piping system.