What precautions should be taken when using non-metallic expansion joints?

Release time:

2022-10-28

To ensure that non-metallic expansion joints are always in good working condition, it’s essential to acquire some knowledge about their maintenance and upkeep. Let’s take a look at the key points to keep in mind when operating and using non-metallic expansion joints. If you’d like to learn more about these issues, come on over and find out!

To ensure that non-metallic expansion joints are always in good working condition, it’s essential to acquire some knowledge about their maintenance and care. Let’s take a look at the key points to keep in mind when operating and using non-metallic expansion joints. If you’d like to learn more about these issues, come on over and find out!

What precautions should be taken when using non-metallic expansion joints?

Non-metallic expansion joints are widely used in flue gas ducts, ventilation pipelines, and engineering applications that require vibration isolation and flexible connections in industries such as power generation, metallurgy, environmental protection, cement and building materials, and petrochemicals. However, during normal operation, the weight of the piping system must be supported by various supports and hangers to allow the piping system to expand and contract freely. These two factors—stability and freedom of movement—are particularly critical during both new plant construction and renovation projects. Moreover, during normal operation, non-metallic expansion joints rely on various pipe racks (hangers) to bear the weight of the piping system. In this particular installation, the flue gas duct weighs 20 tons and is supported by constant-force springs. During the renovation, the piping system was rigidly fixed, causing the constant-force springs to remain in their deformed state without resetting. This situation is primarily due to the unique displacement characteristics of constant-force springs: after the external load is removed, these springs fail to return to their original position. Consequently, after the non-metallic expansion joint is reinstalled, the constant-force springs effectively become unloaded. Once the rigid fixation is released, the weight of the flue gas duct exerts downward pressure, causing the piping system to move downward.

When using non-metallic expansion joints, they serve to prevent pipelines from shifting up, down, left, or right after heating and cooling. Fixed supports should be installed along the pipeline to ensure that its position remains unchanged. On the other hand, the stresses generated by pipeline heating and cooling far exceed the allowable stress levels of steel pipes, fittings, and other accessories. If we want to prevent the pipeline from expanding and contracting, no fixed supports or structural elements can effectively handle this task and guarantee the stable operation of the pipeline system. In addition to these considerations, we also need to pay attention to the fact that multi-dimensional compensation is required—something that non-metallic expansion joints can handle much more effectively. Since system errors are inevitable during pipeline installation, non-metallic expansion joints can better absorb and compensate for such installation inaccuracies. Moreover, the fiber fabric and thermal insulation cotton themselves possess sound-absorbing and vibration-isolating properties, which can significantly reduce noise and vibration in systems such as boilers and fans. Because the primary material is fiber fabric, it is inherently incapable of handling certain types of loads. By using non-metallic expansion joints, we can simplify the design, eliminate the need for large bearings typically required in other types of expansion joints, and thereby save substantial amounts of materials and labor costs. If you have any questions or uncertainties, feel free to call us at any time for consultation. You can also find our contact information on the official website.

The above article introduces the precautions that should be taken when using non-metallic expansion joints. If you’re new to this topic, feel free to give it a read. That’s all for now on the key points—hopefully, this information will be helpful to those concerned. If you have any technical questions about our products, don’t hesitate to reach out and consult with us anytime.

Jiangsu Yaxing

Address: Qingdun Industrial Park, Hai'an City, Jiangsu Province

Phone: 86-513-88483622 ，86-513-88480666,

86-513-88480999

Fax: 86-513-88482423

Email: yx@ntyxbwg.com