Incoloy 825 Coiled Tubing for CO₂ Liquefaction

-- Key Applications of Highly Corrosion-Resistant Coiled Tubing in CO₂ Liquefaction Systems

Explore the critical role of Incoloy 825 coiled tubing in CO₂ liquefaction systems. This highly corrosion-resistant nickel-iron-chromium alloy ensures leak-tightness, enhances heat transfer efficiency, and provides long-term stability for high-pressure carbon capture projects.

During the carbon dioxide liquefaction process, tubing must withstand high pressure, high temperatures, and corrosive gases simultaneously. Under liquefaction conditions, carbon dioxide pressure can exceed 7 MPa, and temperatures approach its critical point of 31.1°C, placing extremely high demands on the system's piping for both leak-tightness and corrosion resistance. Incoloy 825 is a nickel-iron-chromium alloy containing 38% to 46% nickel, 30% to 35% iron, and 20% to 23% chromium, with added copper and molybdenum to enhance resistance to pitting, crevice corrosion, and stress corrosion cracking. Public literature indicates that the corrosion rate of Incoloy 825 in high-chloride environments is less than 0.1 mm per year, making it suitable for the transport of liquefied CO₂ and water-containing gases.

The coil structure allows for continuous piping over long distances, reducing the number of welded joints and thereby lowering the risk of leaks. U-shaped or spiral coil designs increase heat transfer area within limited spaces, improving liquefaction efficiency. For core equipment such as liquefaction towers, heat exchangers, and pre-coolers, the thermal conductivity and mechanical strength of the coil material directly impact energy consumption and system stability.

When designing and selecting materials, engineers typically refer to ASME and ASTM standards to choose Incoloy 825 coils with high corrosion resistance and strength. In actual projects, materials must undergo rigorous dimensional inspection, pressure testing, and corrosion performance verification to ensure long-term stable operation. Through precision manufacturing and high-quality control, Incoloy 825 coiled tubing has become a reliable and durable piping solution for carbon dioxide liquefaction systems, providing a safety guarantee for low-carbon energy projects.