Listed below are the most common types of pipe expansion joints, their differences, and how each functions.
Simple
Simple pipe expansion joints specifically withstand axial forces. Axial forces act upon the pipe’s axis. It is like the force used to crush a can of soda by placing your hands on the top and bottom of the can and pushing one hand to meet the other. Mitigating these crushing forces makes simple expansion joints effective at protecting your pipes.
Universal
Meanwhile, universal expansion joints handle lateral forces and angular rotation in addition to axial forces. Lateral forces act in a perpendicular direction to a plane. So in this case, this would involve holding the soda can as if you were going to drink and pressing the side of it with one hand. Angular forces twist, as if you used your hands to turn against one another and compress the soda can. This is possible because universal joints consist of two bellows and a section of pipe. When axial, lateral, and angular forces are strong, universal joints are a good option.
Pressure Balanced
One specialized type of pipe expansion joint is the pressure balanced expansion joint. These can be either the elbow or in-line variety and are usable when it’s not feasible to anchor a joint to limit axial motion. To ensure the axial forces don’t overwhelm the system, pressure balanced joints employ bellows that oppose one another to cancel some force. Also, the joint contains axial forces because there is a cross-sectional element that stabilizes the joint.
Hinged
Hinged expansion joints, similar to universal joints, address lateral forces primarily. Fitting its name, it’s set apart by the hinge placed near a bellow to bear lateral forces in one orientation. You can also restrict one direction of the hinge by welding and supporting one side and not the other.
Gimbal
Comparable to a hinged joint, a gimbal joint has hinges that allow free movement in any direction. This enables a high degree of pipe movement because it moves with every direction of lateral force. Gimbal joints are good tools for eliminating as much pressure thrust as possible.
If you would like to go with these listed joints or create your own custom metal expansion joints to fit your facility’s unique needs, get in touch with our trusted Triad Bellows team. We have enough industry experience to give you a trustworthy recommendation and the manufacturing know-how to guarantee your satisfaction.
