Read about START-PROF pipe stress analysis software
Axial and Universal expansion joints can be:
Non-Pressure Balanced. Internal pressure creates thrust forces on bellows ends (a), causing pipeline elongation in unrestrained systems (b). In restrained piping between anchors, these thrust forces transfer to supports (c). More...
Semi-Pressure Balanced (Externally Pressurized). This design significantly reduces thrust force. The bellows operates under external pressure within a containment shell vented to atmosphere. Thrust forces are approximately 40% lower than non-pressure balanced designs.
In-line Pressure Balanced. Uses tie rods and balancing bellows to eliminate thrust force completely.
Model axial and pressure balanced expansion joints using custom expansion joint or universal expansion joint elements with zero effective area.
For pressure balanced expansion joints, set thrust area to zero.
Universal Pressure Balanced. Uses tie rods and balancing bellows to eliminate thrust force in multi-plane configurations.
Model this expansion joint type similarly to in-line pressure balanced joints, but place it at L-shaped piping nodes.
