Metal expansion joints manage thermal expansion and vibration in complex ductwork. They provide the necessary capacity for the thermal growth of a piping system, including axial, lateral, and angular movements.
In certain cases, the thrust pressure of a pipe expansion joint must be restrained with tie rods, hinges, or gimbals while still allowing the bellows to move through its design deflections.
These components maintain necessary flexibility within the piping and ducting infrastructure. At US Bellows, we handle a wide variety of project demands. We are currently supplying a 30-inch ductwork system with metal expansion joints for a Canadian uranium mining and exploration company (see below, pictures from the job in progress).
Tailored Approaches for Complex Assemblies
Custom ductwork assemblies can include fabricated elbows, tees, and straight sections made from carbon steel or stainless steel. US Bellows can manufacture these components in diameters of 42 inches or larger. To accommodate varying environmental factors, we fabricate these in carbon or stainless steel.
For an oil and natural gas company in North Texas, we manufactured a 48-inch assembly of SS-304H and Incoloy 800HT Bellows, featuring refractory-lined ductwork that required specialized materials to withstand extreme internal conditions. (pictured top right) In total, we provided over 180 linear ft of refractory-lined ductwork, hardware, and expansion joints. We also fabricated the supports for the ductwork.
For a leading global provider of performance chemicals in La Porte, our project at an acid plant involved replacing five lines of ductwork and metal expansion joints during a turnaround to keep the facility fully operational. The lines were made of both carbon steel and stainless steel, depending on the media and the process. For this ductwork and expansion joints, we provided over 350 linear ft of piping along with the supports and hardware. Pictured below right: product on the way to the plant.
For Piping Engineers: Precision and Proven Design
Piping engineers require system components that meet their exact specifications to handle extreme internal conditions. Metal pipe expansion joints withstand varied design temperatures and pressures while providing the capacity to absorb the piping system’s thermal growth.
These joints expertly handle the required thermal movements. When pressure thrust must be restrained, engineers can use tailored designs featuring tie rods, hinges, or gimbals.
US Bellows further supports engineering teams with finite element analysis, comprehensive product testing, and custom engineering services. We also offer complimentary live webinars and online courses that provide P.E. credits, so your engineering team is at the forefront of the industry.
For Turnaround Planners: Predictability and Speed
Turnaround planners depend on exact timelines to execute successful plant shutdowns. Using the right expansion joints means systems come back online without delays. To support these tight schedules, US Bellows maintains a large inventory of stock bellows to meet urgent needs.
During both planned and unplanned shutdowns, turnaround teams can rely on our quick-turn services and rapid replacement capabilities. Our clients consistently note that our work is always completed exactly when promised, so turnaround schedules don’t change.
For Maintenance Managers and Directors: Problem Resolution and Support
Maintenance leaders focus on maximizing uptime and extending the lifespan of their equipment. Using metal expansion joints prevents unexpected system failures caused by thermal expansion and duct misalignment. When maintenance is needed, US Bellows offers expert on-site services available 24 hours a day, 7 days a week.
For Plant Managers: Overall Operational Excellence
Plant managers need complete confidence that their facility will operate safely year-round. By using custom-fabricated assemblies built from durable carbon steel or stainless steel, plans can safely manage complex ducting systems reaching diameters of 42 inches or larger. US Bellows offers decades of experience, ASME Section VIII-Certification, and over 20 years of EJMA membership to every single project.
FAQ: Metal Expansion Joints and Custom Ductwork
How do I select the right material for a metal expansion joint in custom ductwork?
Selection depends primarily on operating temperature, pressure, and chemical exposure. If the ductwork handles abrasive materials or operates at lower temperatures, carbon steel may be suitable, whereas specialized alloys are needed for more extreme chemical environments.
How do I determine the necessary movement capacity for a custom ductwork expansion joint?
Calculate the total axial expansion (length and change), lateral offset (misalignment), and angular rotation the duct will experience due to thermal fluctuations. A safe design often requires custom prefabricated joints that account for these movements, plus a safety factor to prevent fatigue failure under cyclic thermal loading.
Enhance Your Custom Ductwork with US Bellows
Our on-call engineering and manufacturing team guarantees a response to your request within 48 hours. Need Help? Please refer to our guide How to Select an Expansion Joint.
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