Why Metal Bellows Expansion Joints Are Never Quite Alike

In a sense, no two metal bellows expansion joints are exactly alike.

Metal bellows expansion joints are used in a wide range of fields from energy industries like oil, gas and electric power plants, to aerospace industries like jet engine components, to scores of unique applications as varied landfills, chemical production, and medicine.

Metal bellows expansion joints might be used for pumps, seals, exhaust, ductwork, compressors, system isolation, and more. They might be used in environments where gas pressure is high or low, applications where temperatures are high or low, for installations prone to vibration or movement, and for combinations of the variables.

Each metal bellows expansion joint needs to not only provide the optimal fit for pump, seal, exhaust, ductwork, or other installation at hand, but also to compensate for various stresses from the environment in which they’re being used.

Angular, axial, lateral or rotational movement (or combinations), temperatures that may reach thousands of degrees, and air pressure that might measure in hundreds of pounds per square inch are all factors in determining the final design of a metal bellows expansion joint.

The form of the metal bellows expansion joint always follows its function. And the functions are wide ranging across industries, applications, and environments.

And so in that sense, that each application will have its own unique needs requiring their own unique expansion joints, each metal bellows expansion joint is one of a kind. 

Dozens of Metal Bellows Expansion Joints are far from the Complete List

Metal bellows expansion joints are products of their environment — or, more accurately, they are produced for their environment.

The expansion joints are designed, engineered and built specifically for the specific application in which it will reside.

And since so many uses exist in so many fields, metal bellows expansion joints typically need to be custom designed, engineered and manufactured for a single use at hand.

FlexCom, for example, is commonly prepared to provide more than two dozen styles of metal bellows expansion joints for various industrial applications, and even that is far from the exhaustive list. Each of the 24 styles are customizable on finer points, and entirely new styles can be fabricated for a project at hand.

Our short list of metal bellows expansion joint varieties shows just how diverse the applications can be just in terms of compensating for movement. Before anyone can know just what type of metal bellows expansion joint is truly needed for a job, a thorough engineering consultation is typically required.

FlexCom offerings include pipe expansion joints, stainless steel bellows, exhaust bellows, exhaust expansion joints, rectangle expansion joints and more usually made from stainless steel to handle pressure up to 300 psi or higher and  temperature loads up to 2500°F.

While No 2 Metal Bellows are Exactly Alike, there are Similarities

And yet despite all of the variables that influence their design, metal bellows expansion joints share many similarities.

No matter the application, each expansion joint requires fine attention to detail, strict adherence to careful design and engineering, rigorous testing, and built-in durability to withstand the harshest environments.

While design and engineering will vary depending on the industry, application, and environment, each metal bellows expansion joint, for the optimal application, is likely at the very least to require an experienced custom provider.

An experienced metal bellows provider can perform a thorough engineering consultation and then design, build, and test the metal bellows expansion joint to specification for the most optimal installation.  

Each metal bellows expansion joint is similar in that it is likely to require an experienced provider who can provide the optimal expansion joint for the application at hand.

Metal Bellows Expansion Joints and their Applications

While metal bellows expansion joints share the likely need for an experienced custom provider, the applications, again, do vary widely, which creates a wide range of metal bellows expansion joints.

For Low-Pressure Exhaust Applications

For example, one flexible compensator that FlexCom fabricates is a single metal bellow exhaust expansion joint with a fixed flange on one end and cone flange on the other end. It’s designed for low pressure exhaust environments while withstanding high temperatures as well as axial compression, lateral offset and angular deflection.

This double-flange metal bellows expansion joint may be effective for installations that need to expel clean air or light particulate air at low pressures. An industrial dust filtering operation or a light pollution control system like a baghouse might be a fit for this double-flanged metal bellows expansion joint.

For Low-Pressure Ductwork Applications 

Change one variable, however, and the metal bellows expansion joint likely needs to change as well.

If we’re still working in a low-pressure environment, but now the function of the installation is for ductwork rather than exhaust, a single metal bellow ducting expansion joint becomes a more likely fit.

This expansion joint design is tailored for lower-pressure ductwork, perhaps an industrial air moving installation or airflow modulation so long as the air pressure does not become too great. 

For High-Pressure Applications

Another variable, another metal bellows expansion joint. Higher pressure environments are likely to need yet another type of expansion joint to ensure optimal efficiency and uptime.

In a landfill waste-to-energy plant or other power plants, for example, a gas like methane can  be burned to heat water that becomes steam and then turns a turbine to create electricity. The fuel source, or the steam itself, is likely to cause flutter —  rapid shifts in air or gas pressure that can damage components. Such an installation requires metal bellows expansion joints that mitigate the flutter.

For such a higher-pressure environment, FlexCom might provide a single metal bellow expansion joint with beveled pipe ends and a flow liner.Like the fixed-flange/cone flange metal bellows expansion joint, this expansion joint accounts for temperature and various types of deflection. But the new variable, rapid changes in air pressure, calls for a new expansion joint style, namely the beveled ends and flow liner.

What’s Distinct and What They Have In Common

Each time a variable changes in the industrial application, the metal bellows expansion joint changes.

Since metal bellows expansion joints are used across a wide range of applications, industries, and environments, no two expansion joints, in a sense, are exactly alike.

The expansion joint’s form follows its function, and its function is subject to change based on any of these variables or subsets of variables or their combinations.

What each style of metal bellows expansion joint has in common, however, is that it’s best provided by an experienced manufacturer who can perform a thorough engineering review and then design, build, and test the expansion joint for optimal use in the application.

No matter which in the wide range of expansion joint applications it may be.