Gimbal Expansion Joints are designed to allow angular movement in any plane by the use of two pairs of hinges affixed to a common floating gimbal ring.
These expansion joints can be fabricated with single and multiple arches.
The gimbal ring, hinge and pins, are designed to restrain the pressure thrust due to internal pressure and shear forces.
A gimbal ring is either round or square.
For round gimbals the torsional moment shall be considered and for square gimbals the instability due to the bending shall be considered.
