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Difference Between Metal Bellows and Non-metallic Bellows

Nov. 02, 2022

Metal corrugated conduits - are flexible elements (corrugated conduits), which are designed with relatively thin specifications and can be compressed when pressure is applied from the outside of the vessel (usually made of stainless steel), they are designed to absorb the mechanical and thermal movements expected in service.

Non-metallic corrugated conduits - These are highly flexible connectors made of natural or synthetic fabrics. These non-metallic corrugated conduits and coiled non-metallic dust covers are versatile, multi-purpose seals designed to provide stress relief for thermal movements and mechanical vibrations in the pipeline industry.


Both corrugated conduits have their own utility and importance. If you rate them on a scale of "good", "better" and "best". Of the metal corrugated conduits and non-metallic corrugated  conduits, the metal corrugated conduits with its robust multi-layer design is considered the best. Due to their multi-layer design, these corrugated conduits are used in a wide variety of industrial applications in the pipeline industry. This is because they are considered to be the most reliable and trustworthy in the marine industry for decades.


Advantages of Metal Corrugated Conduits

Higher pressure ranges: up to PN 100

Higher temperature range: up to 1000 °C

In addition to fluids and gases, also suitable for abrasive media and solids

Flexible connection types can be used

Flexible expansion possibilities



Depending on the diameter, non-metallic fittings can typically withstand pressures of up to 250 psi and full vacuum ratings. In metal corrugated conduits, these are designed for pressure capacities up to 1000 psi. The strength of metal is greater than that of non-metal, so metal corrugated conduits are highly advantageous in high pressure applications. However, these metal corrugated conduits are coupled with thrust and used in piping systems/anchors must be designed to handle combined loads.


Advantages of Non-metallic Corrugated Conduits

1. Moisture Resistance

Non-metallic corrugated conduits offer excellent protection against moisture - making them ideal for underground applications and wet areas in industrial and commercial environments. They essentially prevent water, oil and dirt from entering.


2. Corrosion Resistant

Non-metallic corrugated conduits are more resistant to corrosive substances than metal corrugated conduits, and materials such as PVC and polypropylene will not decompose when in contact with salt water or other chemicals.


3. Easy to Install

Non-metallic corrugated conduits are very easy to install. While they are lightweight and designed to keep wires neat and safe, some are separated to make cable insertion easier. This is ideal if you need to replace a damaged or faulty cable and don't have much time.


4. Cost Effective

While all conduits are competitively priced, non-metallic corrugated conduits are often the least expensive option. This is great if you are on a budget and want to protect your cables above or below ground.

Are you interested in learning more about non-metallic corrugated conduits for sale and how they can benefit you? Contact us today to secure an expert consultation!