Single
Motion: Axial, lateral offset (limited) and angular rotation
Simplest and least expensive expansion joint. Lack of built-in control devices calls for strict control of adjacent piping. Lateral or angular motion applications may require tie rods to contain pressure thrust.
Universal
Motion: Lateral offset (large) in any direction
Least expensive for application. As with the single expansion joint, lack of control devices demands careful anchoring and guidance of connected piping. Suitable for low pressure applications only.
Universal Tied
Motion: Lateral offset (large) in any direction
Like the simple (non-tied) Universal expansion joint, the Tied Universal accommodates large lateral offset by virtue of small angular rotations. Tie rods are used to limit center spool motion and contain pressure thrust. This configuration can be used in systems which cannot provide optimum anchoring and guiding.
Pressured Balanced Elbow
Motion: Axial (plus limited lateral and angular)
Eliminates pressure thrust and requirement for main anchors. Minimizes guiding requirement. Frequently used at point of connection to equipment which is sensitive to nozzle loading.