In industrial piping systems, safeguarding against movements and thermal expansion is crucial in maintaining the safety and stability of the system. Many of these systems are subjected to vibrations or movements created during machinery operation, or changing temperatures that cause pressure changes as well as expansion and contraction of machinery parts. While rigid materials like steel or hard plastics can be very durable, they are susceptible to cracking or even exploding under such repeated and prolonged stresses.
For this reason, expansion joints are necessary for systems where movement and expansion are to be expected. The flexibility of expansion joints allows them to alleviate stress on the system, compensating for movements and thermal expansions. While absorbing shock from movements, expansion joints also reduce noise and contribute to a more durable system.
Fabric and metal are two of the most common expansion joint types, used across a wide range of industries and applications. If you are wondering which is a better choice, read on to find out more about the differences between these two types of expansion joints.
What are fabric expansion joints?
Fabric expansion joints are constructed using high-grade synthetic woven materials coated or laminated with elastomers or fluoropolymers. The fabric is supported by a metal frame which provides structure and allows the joint to connect to the ends of the pipe.
As the fabric material is highly flexible, it can allow for a wide range of movements in all directions, including axial (expansion and contraction), lateral (side to side), angular (movement on a pivot), and torsion (twisting) motions.
Other advantages of fabric expansion joints are their adaptability and cost-effectiveness. Fabric is typically cheaper than metal, and the size can be more easily customised to the specific needs of your piping system.
But with every good thing, fabric expansion joints have their limitations. Compared to metal expansion joints, fabric wears out faster and will have to be replaced more frequently. The fabric material is also not suited for handling high temperatures.
What are metal expansion joints?
Metal expansion joints, like fabric ones, do the same job of absorbing shock from movements, alleviating stress on the system, and reducing noise. The main advantages of metal expansion joints are their durability, ability to withstand a wide range of temperatures, and virtually leak-proof capabilities.
As they are often made of durable stainless steel, metal expansion joints do not combust under high temperatures as fabric expansion joints do. The ruggedness of metal expansion joints means it is low-maintenance and should not require frequent replacements. In the long run, this may be a more cost-effective solution in terms of monetary and time costs.
Depending on their construction and purposes, metal expansion joints can compensate for axial, lateral, and angular movements. However, one lacking aspect is the inability to accommodate torsional movements, unlike the capabilities of fabric.
Both fabric and metal expansion joints are useful as compensators in industrial piping systems, but some differences make them more suitable for some uses than others. For example, you should consider factors like temperature, the presence of torsional movement, and customisability in your project requirements to decide on the type of expansion joint you need. If you have a particular need to account for torsional movement, fabric expansion joints may be the better choice. If your system is subject to extreme temperatures, stainless steel is the way to go.
Every piping system is different, from the substance transported to the available space and environmental conditions. If you need advice or a custom-made expansion joint, we recommend consulting experts in industrial parts to design the most suitable solution for your needs. At Pharmchem Engineering, we bring you a decade of experience in supplying industrial engineering parts and customised solutions, including couplings and Teflon hoses in Singapore. Contact us today for all your industrial engineering supply needs!