Metal Versus Rubber Expansion Joints and What They Are Used For

An expansion joint can help relieve stress in piping systems. It also prevents flange gaskets from being crushed. These expansion joints can be made of metal or rubber. Which one is better?

Rubber expansion joings

Rubber expansion joints are flexible connectors made of either natural or synthetic elastomers and fabric. If necessary, internal metallic reinforcements are used to provide stress relief in the piping systems due to thermal movements and mechanical vibrations.

Metal expansion joints

Metal expansion joints are single or multi-walled expansion joints (also known as multi-ply bellows). They are made out of metal (usually stainless steel) and are finished as bellows expansion joints or lens expansion joints. These expansion joints are a flexible element designed to absorbed mechanical and thermal movements expected during service.

Advantages of metal expansion joints

The first advantage to metal expansion joints is that they can resist extremely high temperatures. Depending on the metal, they offer a wide range of temperature resistance-qualities. For example, metal can range from -420 degrees Fahrenheit to 1,800 degrees Fahrenheit. Even more, iron ore as an average melting point of 2,750 degrees Fahrenheit, and stainless steel usually melts at points of 2,500 degrees Fahrenheit. Rubber can’t handle that kind of temperature.

The other advantage of metal expansion joints is the pressure they can handle. Metal joints are designed for pressures up to 1,000-psi whereas rubber can only take 250-psi. The strength of metal is certainly an advantage in high-pressure situations. The relative stiffness or spring rate coupled with thrust forces should be examined carefully though so that you know for sure the expansion joint can handle the pressure required for the job.

What are metal expansion joints used for?

So, what are metal expansion joints used for? Well, metal expansion joints can be used for a variety of applications, including energy production, water treatment, in the paper industries, the chemical industry, and for oil and gas. Simply put, anywhere where exit pipes are used and those pipes experience thermal movements or vibration, the expansion joint is used.

If you’re looking for metal expansion joints that can handle any job you throw at it, give us a call today!