Tantalum Ingots in Corrosion-Resistant Gas Compressor Components

Material selection for the various components of gas compressors is important for durability, reliability, and efficiency over an extended period. In components subjected to attack by aggressive media, tantalum ingots have emerged as a premier choice because of their exceptional corrosion resistance, combined with high-temperature stability.

Fig. 1 Gas Compressor Diagram [1]

Why Use Tantalum in Corrosive Environments?

1. Exceptional Corrosion Resistance

Tantalum is among the most resistant metals against corrosion, mainly in strongly acidic media and aggressive chemical reagents. In fact, it resists acidic gases and liquids more effectively than any other element, which makes it suitable for gas compressors with possible corrosive fractions in the air or gas. For example, in petrochemical refineries, a sulfur-bearing gas can quickly degrade less-resistant materials within hours. By creating a stable, protective oxide layer on its surface, tantalum prevents further corrosion; this increases the lifespan of compressor parts and reduces idle periods.

Related reading: Corrosion resistance of tantalum to water, aqueous solutions and non-metals

2. Outstanding Performance at High Temperature

Most gas compressors are exposed to high-temperature conditions, especially in industries involved in energy. Tantalum can operate under extremely high temperatures due to its very high melting point of 3,017°C (5,463°F). Therefore, tantalum ingots are considered ideal for the manufacture of compressor parts like rotors and pistons that operate at high temperatures, ensuring maximal efficiency.

3. Superior Durability and Strength

The inherent strength and durability of tantalum make it highly suitable for components that undergo continuous mechanical stress. In gas compressors, parts like rotors and valves are exposed to very high shear forces and mechanical wear. The excellent tensile strength and fatigue resistance of tantalum tend to minimise wear, thus extending the lifespan of components even under extreme operating conditions.

Common Applications of Tantalum in Gas Compressors

1. Compressor Rotors and Blades

The rotors and blades in gas compressors experience constant wear and tear due to high-speed rotation combined with the continuous impact of abrasive particles in the gas stream. Tantalum, being highly resistant to abrasion, is applied in the rotors and blades needed to withstand corrosion and mechanical stresses simultaneously. The high melting point of tantalum ensures these components retain their structural integrity, even in compressors operating at elevated temperatures.

2. Seals and Valve Components

The seals and valves of gas compressors provide the necessary tight seal to maintain pressure and prevent gas leakage. Many corrosive environments cause these components to fail, usually due to the gases for which the seals are designed. Tantalum is used to manufacture seals, valve seats, and valve bodies; its resistance to corrosive gases ensures lasting performance and prevents leakage or failure. Its malleability and formability enable the precision manufacturing of complex geometries required in modern compressor systems.

3. High-Pressure Components

Gas compressors operate under very high pressures, consequently placing significant stress on parts such as the compression chambers, flanges, and cylinder heads. The resistance of tantalum to deformation, coupled with its capability to endure extreme pressure variations, makes it highly suitable for such critical components. Applications that would ordinarily fail due to material stress or corrosion can maintain structural integrity and longevity with the use of tantalum.

4. Components of a Heat Exchanger

Gas compressors are used in conjunction with heat exchangers in many industries where temperature changes may occur during or after compression. The tubes and baffles of heat exchangers that are in contact with corrosive hot gases utilise tantalum's exceptional corrosion resistance alongside its good thermal shock resistance. This ensures structural integrity and reliable heat transfer performance under aggressive thermal cycling, where corrosion would degrade other materials.

Corrosion Resistance: Tantalum and Other Materials

Though stainless steel, titanium, and nickel-based alloys have wide applications in gas compressors, they do not match tantalum in terms of corrosion resistance and high-temperature stability. Below is a brief comparison of tantalum against other materials. For more metal products, please check Stanford Advanced Materials (SAM).

Conclusion

Tantalum ingots provide significant advantages in compressor applications requiring high corrosion resistance and stability at elevated temperatures. Other materials, including those made of stainless steel and titanium, have their specific roles, but tantalum remains the primary material for very harsh industrial environments where high performance, reliability, and extended service life are crucial.

Reference:

[1] Eugene "Buddy" Broerman, Tim Manthey, Jürgen Wennemar, Justin Hollingsworth, Chapter 6 - Screw Compressors, Editor(s): Klaus Brun, Rainer Kurz, Compression Machinery for Oil and Gas, Gulf Professional Publishing, 2019, Pages 253-307, ISBN 9780128146835.