Universal expansion joint to absorb lateral movement
Shows a tied universal expansion joint used to absorb lateral deflection in a single plane
“Z” bend. Where dimensionally feasible, the expansion joint should be designed to fill the entire offset leg so that its expansion is absorbed within the tie rods as axial movement.
The tie rod should be extended to the elbow centre line when practical. The thermal movement of the horizontal lines is absorbed as lateral deflection by the expansion joint.
Only directional guiding is required since the compressive loading on the pipe consists only of the force necessary to deflect the expansion joint. Any thermal expansion of the offset leg external to the tie rods, such as that part of the elbows at either end, must be absorbed by bending of the horizontal pipe legs.
Provisions should be made in the design of the guides to allow for both this deflection and the reduced length of the expansion joint in its deflected position.